Is There Value in Ideas You Can’t Remember?

When I give learning advice, as a rule, I suggest active recall. That’s the process of giving the answer to the question without looking at the solution.

The best way to understand active recall is to look at more passive review strategies. Rereading notes, for example, is not active recall because you never need to produce the answer to a question without looking at it. Instead you are simply making the ideas increasingly familiar.

Students, for the most part, should focus on active recall strategies, not passive ones. The majority of testing methods for academic subjects focus on being able to retrieve an answer, from a question, without looking at your notes. Even open-book exams or assignments require recall, since you have to recall at least enough to know where to locate the answer in your notes.

For practical subjects, recall is also important. To speak a language, you need to be able to produce sentences without a translator. It doesn’t suffice to enter the sentence into Google Translate and feel like you knew it all along.

Given the prevailing importance of recall for both students and practical learners, it might be worth asking whether there is any point in learning something if you can’t recall it later. Despite the weaker value of unrecallable information, I believe there are still a lot of cases where it can be useful to have learned things you can’t recall.

What Does it Mean to Recall Information?

First, I think it makes sense to clarify a definition of recall. I would define recall as being able to retrieve a piece of information, given a particular prompt. The choice of prompt is important, however, as some information may be recallable under certain prompts but not others. (I’d add that I suspect that all information requires some prompt to be able to recall it, but that for really flexible knowledge the range of prompts is large enough that specifying it isn’t necessary.)

This point may be confusing, so I’ll give an example. I’ve spent the last two years learning Chinese characters, with around half of them having been learned during my stay in China. According to Anki, I’ve learned roughly 2500 characters, and with a successful recall percentage of 85%, that means I probably “know” about 2100 of them.

However, in all of these cases, what I “know” is being able to correctly state the pronunciation and meaning of a character, given its image as a prompt. This is a skill very useful for reading and writing characters using alphabetic input.

I have learned how to handwrite some characters, but it is far less than 2100. If being able to successfully recall and handwrite a character counts as “knowing” it, I would guess I only “know” around 100 characters.

So which is it? Am I able to recall 100 characters or 2100?

It simply doesn’t make sense to talk about what information you can recall without also including the prompt. In this case, I can recall 2100 characters’ meaning and pronunciation, given the image, but I can only recall how to produce the image given the definition in a small fraction of those cases.

The same is true of learning other foreign vocabulary words. Often it is possible to recall the meaning of a foreign word, but not be able to produce the word, given the meaning. Saying that I only “recognize” the word in one case but “recall” it in another is incorrect. It’s more accurate to say that I am able to recall the meaning, given the word, but not recall the word given the meaning.

For information to be truly unrecallable, there would be no prompts that could bring the information up. However, as a practical measure, I’ll call information unrecallable if the only prompts that can bring the information up contain so much of the original information that they aren’t going to be useful in practice (for example, showing 95% of the image of a Chinese character isn’t a useful prompt for “recalling” the remaining 5%).

Is There Any Benefit to Unrecallable Information?

Given our definition—that recallable information is information that you can access, given a range of at least somewhat useful prompts, does unrecallable information have any value?

Maybe it will be helpful to reword this example more specifically: if you read a book which you can’t recall any of the contents, the thesis, ideas or suggestions, was there any point in reading the book?

Obviously a book you can’t recall anything from is less valuable than one you can. But I’d like to argue that, contrary to popular wisdom, there is still value in a book you can’t recall.

The value of unrecallable information could potentially come from two different places.

  1. Unrecallable information can be relearned faster.
  2. Unrecallable information can have unconscious influences on how you process future information.

Relearning Information You’ve Forgotten

The first value of unrecallable information is that it can be relearned faster. One way this might work is that recall requires a certain threshold of activation to retrieve. Any pattern of memory laid down that is below this threshold can’t be accessed directly.

However, just because it can’t be accessed doesn’t mean it doesn’t exist. If you were to relearn the information, those inaccessible patterns might get boosted back to threshold, and be retrievable again. Since the pattern was already there in a weakened form, it will require less practice than learning the first time.

Forgotten Ideas Influencing What You Learn Now

An alternative effect could be that forgotten information will influence future learning, even if it is no longer directly accessible. Paul Graham has an essay here where he muses about this possible value of forgotten ideas.

It’s hard to come up with examples of this effect because, in order to be a true example, we must necessarily be unaware of its impact. But I’ve had many experiences of information that was only weakly recallable influencing my beliefs, so it’s hard for me to believe that the effect would suddenly have zero impact once they go below threshold.

One pseudo-example of this type, was when I was reading an article that was supportive of group selection in biology. At the time, I had not remembered reading a book arguing against group selection and the specific arguments made against it were completely lost to me. But I recall feeling skeptical of the new article I read, nonetheless. It was only later did I stumble upon the old book and realized that I had read an argument against group selection previously.

Similarly, I might forget how to say a particular word in Spanish, but if someone suggests an incorrect word to me, I may have a feeling it is wrong, even though I’m unable to recall the correct word.

Why Value Forgotten Ideas?

Obviously recall matters. And, as a rule, I still recommend practicing active recall when learning, with few exceptions. But I worry that by promoting active recall as a successful strategy, there is a tendency to believe that information which can’t be recalled might as well not be there in our brains.

I sometimes hear from people who stress because they feel they’ve forgotten most of the things they learned in school, books or past experiences. While this is unfortunate, the conclusion that they draw, that therefore there is no current value in any of these experiences is wrong. Information, even if it feels forgotten, can still have subtle, useful effects.

If I spend my life reading books, and I end up having read 5000 books, it would seem quite a shame if I couldn’t recall the main ideas and arguments of 3000 of them. But, I wouldn’t argue that I would be exactly as smart about all things had I only read the 2000 for which I can actively recall. The silent 3000 influence my ability to relearn and shape what I believe even if their traces in my brain are no longer directly accessible to me.

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  • Anya

    I love to read and sometimes also re-read. Lately I’ve been feeling that maybe a re-read is a probable waste of time, when there is so much out there to peruse. I would like to believe that whatever you read, encounter or experience gets absorbed into your sub- conscious through something like mental osmosis. Else, you feel like a total waste for not recalling everything uve read.

  • Anya

    I love to read and sometimes also re-read. Lately I’ve been feeling that maybe a re-read is a probable waste of time, when there is so much out there to peruse. I would like to believe that whatever you read, encounter or experience gets absorbed into your sub- conscious through something like mental osmosis. Else, you feel like a total waste for not recalling everything uve read.

  • Caleb Andersen

    Thanks Scott, love this article! I’ve been thinking about this a lot recently myself. I absolutely agree that there is value in forgotten ideas because just as you said, under the threshold it is still able to influence our ability to learn future information and form our perspective of the world in the present as well. There is science behind this even! Also, I appreciate your personal examples as well.

  • Caleb Andersen

    Thanks Scott, love this article! I’ve been thinking about this a lot recently myself. I absolutely agree that there is value in forgotten ideas because just as you said, under the threshold it is still able to influence our ability to learn future information and form our perspective of the world in the present as well. There is science behind this even! Also, I appreciate your personal examples as well.

  • José Antonio Fajardo

    Hello Scott, you should consider have a facebook account, it would be easier and faster to read your articles.

  • José Antonio Fajardo

    Hello Scott, you should consider have a facebook account, it would be easier and faster to read your articles.

  • Nice post, Scott. I definitely see how forgotten information can be of benefit to an individual relearning something but I wanted to ask your opinion on macro level processes caused by a similar phenomenon. Specifically how the ‘sleeper effect’ (where one can recall a piece of information but not the original source or it’s status as a reputable information provider) may be creating a lot of the misinformation we hear commonly and see nearly everyday on various social media platforms. I recently wrote about the whole “exercise makes you happy because endorphins” myth and concluded that such things perpetuate for years largely due to humans just feeling awkward confronting another in such a way. I think the idea that you just hear or read something once can be somewhat damaging for this reason. Thoughts?

  • James Emry

    Nice post, Scott. I definitely see how forgotten information can be of benefit to an individual relearning something but I wanted to ask your opinion on macro level processes caused by a similar phenomenon. Specifically how the ‘sleeper effect’ (where one can recall a piece of information but not the original source or it’s status as a reputable information provider) may be creating a lot of the misinformation we hear commonly and see nearly everyday on various social media platforms. I recently wrote about the whole “exercise makes you happy because endorphins” myth and concluded that such things perpetuate for years largely due to humans just feeling awkward confronting another in such a way. I think the idea that you just hear or read something once can be somewhat damaging for this reason. Thoughts?

  • Karina

    I see this a lot in language learning. My students often forget their vocabulary words but words that they have been exposed to before come back to them much quicker. Same with me. I often used to worry about my forgetfulness but knowing this, I don’t feel like my time is wasted all that much.

  • Karina

    I see this a lot in language learning. My students often forget their vocabulary words but words that they have been exposed to before come back to them much quicker. Same with me. I often used to worry about my forgetfulness but knowing this, I don’t feel like my time is wasted all that much.

  • Luis Garcia de la Fuente

    Someone told me once that the most valuable knowledge is ‘what remains’ once you forget what you have learnt…

  • Luis Garcia

    Someone told me once that the most valuable knowledge is ‘what remains’ once you forget what you have learnt…

  • Andrew Dennis Balitsky

    Scott, you usually do a good job of giving the how/why of learning to your readers, but I think you’re dropping the ball here. Let’s stay with your book-I’ve-read-and-forgotten example. There’s an elephant in the room and you’re tiptoeing around. What about discussing the actual _act_ of learning, rather than much later consequences of said learning?

    Ok, sure, there might be something of a subconscious effect that resides long after you’ve read and forgotten a book. I agree. Let’s call this the residual effect of the book’s knowledge. But what about the residual effects of the process of reading the book?

    First and foremost (imo), it’s a workout for your focus muscle. While reading, you don’t check your facebook or twitter or stare out the window. You beam your attention on a sentence/page at a time. That’s powerful. Other potential benefits…

    – You learn how to learn. Maybe you forget your first book. And your second. Then you grab a highlighter for the third. By the time you reach the tenth (or 20th, 30th, whatever), you’re taking notes and highlighting and recalling and mastering how to learn.

    – Idea storm. When reading an interesting book, the idea sea is churning. Waves crash. Lightning strikes. If it’s a good enough book, I’ll catch myself wondering about it for several days after. Maybe weeks. If, as I’ve read on your site before, ‘memory is the residue of thought’, how do you know that the residual effects of a book’s knowledge aren’t from this gestation period of the book’s ideas after the fact? (rather than stemming from the initial act of absorption)

    – Discussion. If I talk about a book I’m reading, the likelihood that its information sticks goes off the chart. Why? I don’t know. Maybe the combo of reading/recall/discussion/interaction provides the information tent with 3 more stakes to nail in the brainy ground than just reading alone.

    – Inspiration. A lot of books that I read move me inspired me to action — on that exact day. I stopped eating fast food after Fast Food Nation. I started writing after Tolkien/Salvatore. I practiced active recall after Higbee’s “Your Memory”. Some of those actions were short lived. Some were not. Some I continued for years. The action went on even after I couldn’t remember a single chapter from the book, as a matter of habit. And don’t we learn to take better action in our lives?

    Notice, most of these examples I’ve mentioned fall outside the category of active recall. Yes, not even the discussion bit (*see below). Maybe some of them you can repackage as residual effects of a book’s knowledge. But I see them as natural extensions of sitting down to read. Sure, some time down the line you’ll forget what you’ve read today. But the moment you stand up, you’re supercharged.

    *Ok, technically, active recall is indeed a part of discussion. But I’m viewing active recall as forcing yourself to sit down and pull a thought out of your brain, as part of learning. Whereas discussion, for me, happens sometime after the learning session and in a totally casual setting. And there’s a lot more to discussion than fetching files from the brain folder.

  • Sunnysellsflorida

    good info-but too long and wordy-PLEASE make more succinct-thank you…

  • Sunnysellsflorida

    good info-but too long and wordy-PLEASE make more succinct-thank you…

  • Cougar_B

    I don’t have the time or attention to learn a language, but I do have the time and interest to read a book in Spanish with the help of Google Translate. I set it up so that I translate a paragraph, then read it in Spanish without help, then read the previous paragraph without help, then read the current paragraph without help, and then listen to the robot voice read both paragraphs while I review the words visually.

    It’s a novel, which keeps my interest up. There’s lots of review, which helps me learn individual words more easily. It’s a little like immersion learning, because I’m exposed to everything in context and I’m focused on the whole context. When I talk to a Spanish friend, I don’t have the confidence or ability to speak in Spanish, yet, but I regularly translate individual words in our conversation. So I’m actually learning something.

    When I’m done with this novel, I’ll go back to some flashcards with Anki and master a lot more with the ability to recall more completely. Perhaps I’ll listen a little more to Pimsleur. Then I’ll read a different novel or short story. Eventually, I’ll study a little grammar.

    I believe that the natural approach to learning language–in context and without lots of strenuous recall exercises–feels best to me. Focusing only on recall is hard work, and this is fun. If it was only hard work, I’d give up too soon, like I have way too often in my life.

    If it ain’t fun, it don’t get done.

    PS. Interesting. I just noticed where you live. I live in Aldergrove, but I was subscribed while still in the US.

  • Cougar_B

    I don’t have the time or attention to learn a language, but I do have the time and interest to read a book in Spanish with the help of Google Translate. I set it up so that I translate a paragraph, then read it in Spanish without help, then read the previous paragraph without help, then read the current paragraph without help, and then listen to the robot voice read both paragraphs while I review the words visually.

    It’s a novel, which keeps my interest up. There’s lots of review, which helps me learn individual words more easily. It’s a little like immersion learning, because I’m exposed to everything in context and I’m focused on the whole context. When I talk to a Spanish friend, I don’t have the confidence or ability to speak in Spanish, yet, but I regularly translate individual words in our conversation. So I’m actually learning something.

    When I’m done with this novel, I’ll go back to some flashcards with Anki and master a lot more with the ability to recall more completely. Perhaps I’ll listen a little more to Pimsleur. Then I’ll read a different novel or short story. Eventually, I’ll study a little grammar.

    I believe that the natural approach to learning language–in context and without lots of strenuous recall exercises–feels best to me. Focusing only on recall is hard work, and this is fun. If it was only hard work, I’d give up too soon, like I have way too often in my life.

    If it ain’t fun, it don’t get done.

    PS. Interesting. I just noticed where you live. I live in Aldergrove, but I was subscribed while still in the US.

  • L. Amber Wilcox-O’Hearn

    Great points. One thing we know from cognitive science is that we much more easily forget the source of our beliefs than the beliefs themselves. So, like your biology example, we form conclusions, I.e. we learn from our experiences, even when we don’t recall the experiences.

  • L. Amber Wilcox-O’Hearn

    Great points. One thing we know from cognitive science is that we much more easily forget the source of our beliefs than the beliefs themselves. So, like your biology example, we form conclusions, I.e. we learn from our experiences, even when we don’t recall the experiences.

  • Aldo Garbellini

    Last sentence really great.

  • Aldo Garbellini

    Last sentence really great.

  • Aldo Garbellini

    The length was about right.

  • Aldo Garbellini

    The length was about right.

  • Stephen Anderson

    Interesting topic. While I was in Japan studying acupuncture I decided that I would study the college graduates list of Kanji (2042 characters). I decided to used Harry Lorraynes peg word method as I wanted to be able to recall all of these characters without any prompts so I could know what I’d truley remembered and what I’d forgotten. I would learn 100 at a time. In the end I could write the whole book from my head without any prompting at all. Occasionally I would get stuck on one word/character that I’d forgotten so I would go back to the book and reinforce the association between the peg and the character I was learning and then the next day rewrite that set of 100. This took me about one year to achieve but truley accelerated my reading, writing, and speaking of the langauge. I guess this is a way to make unrecallable recallable. My biggest challenge is deciding what I want to spend the time making recallable.

  • Stephen Anderson

    Interesting topic. While I was in Japan studying acupuncture I decided that I would study the college graduates list of Kanji (2042 characters). I decided to used Harry Lorraynes peg word method as I wanted to be able to recall all of these characters without any prompts so I could know what I’d truley remembered and what I’d forgotten. I would learn 100 at a time. In the end I could write the whole book from my head without any prompting at all. Occasionally I would get stuck on one word/character that I’d forgotten so I would go back to the book and reinforce the association between the peg and the character I was learning and then the next day rewrite that set of 100. This took me about one year to achieve but truley accelerated my reading, writing, and speaking of the langauge. I guess this is a way to make unrecallable recallable. My biggest challenge is deciding what I want to spend the time making recallable.

  • Scott Young

    Possibly. But I think the problem is simply that in order to know the “exercise makes you happy b/c endorphins” is a myth, you need to be informed of its myth-status from someone more credible that your initial first source. I would say people tend to take things at face value unless it contradicts their previous network of beliefs.

    I guess I’m skeptical that remembering sources would make people better at distinguishing true and false beliefs, unless those beliefs are about the very nature of the sources themselves (like properly attributed quotations)

  • Scott Young

    That’s something I’m contemplating. Thanks!

  • Scott Young

    Possibly. But I think the problem is simply that in order to know the “exercise makes you happy b/c endorphins” is a myth, you need to be informed of its myth-status from someone more credible that your initial first source. I would say people tend to take things at face value unless it contradicts their previous network of beliefs.

    I guess I’m skeptical that remembering sources would make people better at distinguishing true and false beliefs, unless those beliefs are about the very nature of the sources themselves (like properly attributed quotations)

  • Scott Young

    That’s something I’m contemplating. Thanks!

  • Scott Young

    Well I’m not arguing that active recall is the only way to learn information. Simply contrasting the two beliefs I hold (a) that active recall is one of the better ways to retain information and (b) that a lot of the value of information doesn’t rely on it being explicitly recallable.

  • Scott Young

    Well I’m not arguing that active recall is the only way to learn information. Simply contrasting the two beliefs I hold (a) that active recall is one of the better ways to retain information and (b) that a lot of the value of information doesn’t rely on it being explicitly recallable.

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