102 Lessons from the 102 Books I Read This Year

As part of my Foundations project, I read 102 books over the past twelve-and-a-half months.¹

That includes seven textbooks and dozens of academic books, in addition to the popular science and self-help books I selected for each theme.²

Those interested in brief reviews of each book can check out my reading lists for each topic: fitness, productivity, money, food, reading, outreach, sleep, reflection, connection, focus, organization and service.

I’m hardly unique in my reading volume, but for those interested in knowing how I get through 100+ books per year, I’ll leave some explanation in the footnote here.³

Here are the most interesting things I learned this year while reading 102 books:

On Fitness

1. Exercising regularly is probably the single best thing you can do for your health. (Outside of quitting smoking.)
2. While we evolved hunger to stay fed and thirst to avoid dehydration, we never evolved a drive to exercise. As a result, we move far less than we should to stay healthy.
3. Regular exercise cuts your risk of an early death by 40%, roughly the same benefit as quitting smoking.
4. Experts recommend everyone gets 150 minutes of moderate (or 75 minutes of vigorous) cardio per week. But the health benefits continue to accrue beyond this level.
5. What counts as “moderate” or “vigorous”? Use the sing/talk test. Moderate exercise means you can talk but can’t sing while exercising. Vigorous exercise makes it hard to talk without interruptions to take a breath.
6. Aerobic and strength training offer distinct health benefits. Aerobic training matters more for living longer. Strength training is crucial for maintaining bone density and avoiding frailty.
7. Stretching is overrated. It doesn’t prevent injury or soreness, and it can temporarily weaken your muscles. But it may help for improving range of motion.
8. In self-report surveys, a majority of Americans claim they get the recommended 150 minutes of moderate activity per week. But when researchers measured activity directly, fewer than ten percent met the recommendation.
9. Chronic lower back pain is probably a side-effect of comfy chairs and mattresses that keep our core muscles weak.
10. Humans are the ultimate long-distance runners. Upright posture and sweat mean that even though we can’t outrun a gazelle, we can outlast one in the heat.
11. It’s a myth that running ruins your knees. While running injuries are common, the long-term effects of running include strengthening bones and tendons, so that, in the long-run, recreational runners don’t actually have high rates of injury.
12. If you do want to avoid running injuries, it helps to run barefoot (or, as if you were running barefoot). Heavy cushioning in shoes can, ironically, make injuries more likely by encouraging a heel-striking stride.
13. If you want to strengthen your mind, exercise. Brain training games don’t work, but regular exercise enhances cognition and helps stave off dementia.
14. Exercise also improves your mood, and it is even used as a frontline treatment for depression.

On Productivity

1. Happiness, not stress, leads to productivity.
2. A sense of progress, in turn, is the most important factor to workplace well-being. (But in surveys, managers thought it was the least important factor!)
3. One setback erases the good of three positive experiences of progress.
4. Checklists save lives. Adopting one reduced infections from 4% to zero at Johns Hopkins, preventing 1500 deaths and saving nearly $200 million.
5. Track both lead and lag metrics. Lag metrics are what you care about (but can’t directly influence). Lead metrics are what you can influence (but often require more work to measure). Think: scale weight vs. food consumption for a weight-loss goal.
6. Despite our preconceptions, we may be happier at work than at home. People experience more flow at work than in leisure.
7. Energy, not time, is the limited resource in our ability to be productive.
8. Procrastination comes from poor impulse control, not perfectionism.

On Money

1. You can’t beat the market. Nearly everyone is better off simply buying a diversified low-cost index fund.
2. Neither can any fund you invest in. The percentage of funds that beat the market after fees is so low that you can round it to zero.
3. You can’t time the market. Frequent trades expose you to taxes and whittle away your capital on fees. Buy and hold is better.
4. If you have dependents, get term (not whole) life insurance. You want financial protection in the case of catastrophe—the “investment” aspect is overrated.
5. Bonds may actually be riskier than stocks over long time horizons.
6. Pay yourself first. Switching from opt-in to opt-out dramatically increases retirement contributions. You won’t miss money that’s automatically saved, but you’re unlikely to voluntarily save what’s left over at the end.
7. If you need an advisor, find someone who charges hourly. Paying a percentage of your assets seems cheaper, but the cost is enormous in the long-run.
8. Start saving young. Warren Buffet’s amazing wealth is largely a function of his age, not his skill. If he started at 30 and retired at 65 (as opposed to the nearly 80 years of uninterrupted investing he has had), his net worth would be only $11 million (as opposed to $142 billion).

On Food

1. Despite popular impressions, dietary guidelines don’t actually change all that much, and following them is healthy for you.
2. The guidelines recommend a dietary pattern that is high in fresh fruits and vegetables, whole grains, seeds, nuts and legumes. It has moderate amounts of fish, low-fat dairy and lean protein. It is low in salt, processed red meat and saturated fat.
3. Almost nobody follows these guidelines.
4. Saturated fat is still bad for you. This is not controversial among experts. Stop saying butter is a health food.
5. The reason saturated fat is discouraged is because it raises LDL cholesterol, which leads to atherosclerosis. The damage accumulates over decades, so the time to eat better is well before you get heart disease.
6. We’re overweight because we eat too much. The increase in calories consumed is enough to entirely explain the change in body mass.
7. We overeat because our brain’s circuits are highly sensitive to starvation and only weakly sensitive to gaining too much fat.
8. All diets work the same way, by causing you to eat fewer calories than you burn. Whether you do intermittent fasting, low-carb, low-fat, vegan or meal planning, what matters is that you can stick with it.
9. Most diets fail, and of those that succeed, most people do not keep off the weight.
10. Successful weight loss requires you to stick to a dietary pattern forever. If you go back to old habits, you’ll regain the weight. Even many of those who believe they’re sticking to the dietary patterns that led to weight loss can regain the weight by subtly consuming more calories.
11. Although multivitamins are controversial, some supplementation is probably a decent insurance policy (although not a substitute for real food), especially if you are older.
12. Athletes should be careful with a low-carb diet. Fat cannot be burned without oxygen, so when glucose reserves are low, the body must use protein instead.
13. While an all-plant based diet *can* be healthy, vegans are at a higher risk of nutritional deficiencies in certain micronutrients, particularly B12, zinc and iron. Omega-3 fatty acids DHA and EPA may also be too low since the body converts them from ALA (the most common plant Omega-3) at negligible amounts.

On Reading

1. We evolved to read by coopting neuronal circuitry that was built for shape and face recognition. This means literate people are actually somewhat worse at recognizing faces than illiterate cultures!
2. We read by processing nearly every word in the text, and by viewing nearly every letter. This skill is so overlearned in experienced readers that it takes careful experiments to demonstrate that this is what our brains are doing.
3. The best way to teach reading is through phonics. Early readers have not yet built this neural circuitry, so they benefit from strengthening the sound-spelling correspondence through direct instruction.
4. This also means speed reading techniques don’t work. The physics of eye movements and neural processing puts a hard upper limit of about 500 words per minute.
5. The way to read faster is simply to read more. While the biomechanics of reading prevent reaching the insane speeds proposed by some speed readers, prior knowledge is a major enhancer of retention and fluency, which makes reading more productive and enjoyable.

On Outreach

1. Loneliness is as bad for your health as smoking cigarettes.
2. Social isolation kills, in part, because the stress of loneliness weakens our immune system.
3. Despite this, we socialize less than we used to. Participation in all forms of community life has been on a steady decline since the 1960s.
4. It takes longer to make a friend than you think—over sixty hours of contact were needed in one study.
5. But doing unusual events in an unfamiliar environment can help build closeness.
6. So can asking the right questions. We default to small talk, but asking the right questions can accelerate intimacy.
7. Friendliness is irrationally undersupplied. In one study, subjects were asked to either stay quiet or talk to a stranger during their commute. People predicted they’d prefer solitude, but they enjoyed the conversation more.
8. There are numerous explanations, but a simple one is just better entertainment. Why hang out with friends when you can watch Friends on television?
9. Weaker community ties mean less trust, civic virtue and a weakening of democracy.
10. It’s not all about close friendships either. Weak ties are key to finding opportunities and connections which bridge social groups and maintain social capital.

On Sleep

1. Despite being near-universal in the animal kingdom, there is still no scientific consensus as to the primary function of sleep.
2. That may be because sleep serves too many functions. Sleep flushes the brain of metabolic byproducts, consolidates memories, reinforces the immune system and recalibrates synaptic connections.
3. If you don’t sleep you’ll die. Studies with rats show that sustained sleep deprivation is invariably fatal, and humans with a genetic condition that prevents sleep generally die within 6 to 36 months after symptoms begin.
4. Even mild sleep deprivation has enormous cognitive consequences. Being awake for 24 hours straight has similar effects to being legally drunk.
5. But effects of sleep deprivation are uneven. It’s worst for vigilance (which is why driving sleepy is so dangerous), but it has almost no impact on intelligence tests.
6. Worse, even though our subjective feeling of sleepiness levels off after awhile, our ability to function continues to decline. This means we don’t realize how much our lack of sleep is lowering our performance.
7. The damage sleep deprivation does to the immune system has encouraged the International Agency for Research on Cancer to list shift work as a probable carcinogen.
8. But if you have insomnia, don’t worry, you probably are sleeping enough. If you’re sleep deprived you will fall asleep, so despite feeling cranky and low energy, most insomniacs are not actually sleep deprived.
9. The most successful treatment for insomnia isn’t pills, but CBT-I, a kind of therapy that works by restricting sleep to a controlled window. This helps to build sufficient sleep pressure to sleep consistently.
10. By now, most of us know that too much light before bedtime disrupts our circadian rhythm, making it hard to go to sleep. But the opposite is also true—insufficient light in the middle of the day (from being indoors) also causes problems. Make sure to get your sunshine!
11. We know even less about the function of dreams than we do for the function of sleep. One theory suggests it may be used in reinforcing negative information. This is curiously related to the fact that SSRIs, which are used to treat depression, also have the side-effect (or primary effect?) of greatly reducing REM sleep.

On Reflection

1. The world looks panoramic and vibrant, but outside of a narrow patch of central vision we see everything in a blurry grey.
2. Similarly, our feelings and rationalizations tend to be incredibly shallow—we consider few examples before forming a judgement about the whole picture.
3. Psychoanalysis is pseudoscience. Modern, scientifically validated therapy deals with your manifest feelings, beliefs, and behavior, and has much less emphasis on dreams and the unconscious.
4. Meditation might rewire your brain. But the benefits seem to accrue most to those who meditate far more than ten thousand hours.
5. Asking yourself “what went well?” at the end of the day can give you a big boost to your happiness.

On Connection

1. Married people are happier than non-married people. This is true even if if you control for gender, age, children, cohabitation, education, income and even frequency of sex.
2. While it helps to have compatible values and interests, there’s a “better” personality for relationships—people higher in agreeableness and lower in neuroticism have more stable relationships, regardless of their spouse.
3. Researchers can predict who will break up to >91% accuracy, simply by watching how they handle disagreements.
4. Catharsis is a myth. Expressing anger tends to make you more angry, not less. Calm down, count to ten and talk it out instead.
5. Despite stereotypes, men tend to be more romantic in their relationship beliefs, while women tend to be more pragmatic.
6. Couples are happier when men and women are “androgynous” or high in both expressive (stereotypically female) and instrumental (stereotypically male) personality traits.
7. Men and women are far more alike than different. (Attitudes towards sex being one of the few major exceptions.)

On Focus

1. ADHD is about as heritable as height, is not caused by parenting style, doesn’t go away as you age and, despite popular disbelief, medication works pretty well.
2. The brain structures responsible for sustaining deliberate focus are among the last to mature and the first to decline as we age.
3. Multitasking is a myth. What appears to be multitasking is actually rapid task switching.
4. People who think they’re good at multitasking usually aren’t.
5. A study of office workers found that they were interrupted in their task roughly every three minutes. Half of those interruptions were self-inflicted.
6. Even having a phone nearby reduces our mental bandwidth and makes us seem less attentive in conversations.
7. We chastise ourselves for not being more productive. But working too much is actually one of the top regrets people have at the end of their lives.

On Organization

1. It’s better to declutter by category than by place.
2. Tidying should focus first on getting rid of unnecessary stuff, and only secondarily on storing it away.
3. We overvalue things we own, merely because we own them. 
4. Hoarding disorder is debilitating and very difficult to treat.
5. This is, in part, because the experience of hoarding has positive, obsessional aspects (like other impulse-control disorders, such as addictive behavior), as well as negative, anxiety-like aspects (such as OCD).

On Service

1. Donating money to the most effective charities, it takes roughly $3500-$5000 to save a person’s life.
2. The most effective charities are 10x to 100x as effective as mediocre charities.
3. This is because many good-sounding ideas that raise money don’t actually work well. Some ongoing charitable efforts actually do worse than nothing.
4. Despite this, the average Westerner gives less than 2% to any charitable causes, (including many dubious acts of philanthropy like this one).
5. When asked to guess how much of the US budget goes to foreign aid, respondents guessed around one third. The actual amount is less than 1%.
6. “Ethical” consumerism is overrated. Fair-trade doesn’t help poor farmers. Avoiding “sweat shop” labor may make people in poorer countries worse off. If you want to help, save the premium price and give it directly instead.
7. Chunk your helping. People who volunteer in bigger chunks (say one day per week) get more benefits than those who do so every day, perhaps because it makes the act more salient.
8. Givers tend to end up on both the top and bottom of the success ladder.
9. Empathy is overrated. It’s biased, innumerate and is just as likely to harm as to help. Compassion plus reason is better.

1. Technically I read 105, as I finished three other books that I didn’t include in my monthly reviews: Ezra Klein and Derek Thompson’s Abundance, Alexandre Dumas’s Le Comte de
   Monte-Cristo on audiobook, as well as Matt Fitzgerald’s 80/20 Running. I also made some decent headway into Anthony Yu’s translation of the Chinese classic Journey to the West and Leo Tolstoy’s War and Peace.
2. For the vast majority of these books, I read them cover-to-cover. For a couple of the textbooks, notably the two 1000+ page finance textbooks, I read well over half, but I skipped some chapters that weren’t relevant to my interests. I decided not to include the dozens of books I started but decided not to finish.
3. In brief, you can read a lot of books if you spend a lot of time reading. Producing the companion course to this project was my full-time job this year, so reading and research was, in a sense, my job. Beyond that, I benefitted greatly from Audible, with at least half of my “reads” this month being listens, which allowed me to finish a lot of books during my commutes, walks and workouts. Finally, if you read more, you read faster and with better retention, so reading lots of books becomes a self-reinforcing cycle.