Why We Sleep is doubtlessly one of the best self-help books I’ve read since 7 Habits.

This book (one might say ironically) opened my eyes to the myriad benefits of sleep, and the multitudes of deleterious effects even the slightest lack of sleep can have on the human body and mind. Instead of writing about how amazing this book is, I present short highlights, along with my thoughts that will hopefully drive any readers straight to this book, and to a superior lifestyle:

On Waking Up Late

An adult’s owlness or larkness, also known as their chronotype, is strongly determined by genetics. If you are a night owl, it’s likely that one (or both) of your parents is a night owl.

For years I have scolded mentees for an apparent lack of discipline in waking up early, and that it is their choice to have that sort of lifestyle, of sleeping late and waking up late. I now recognize the error in my thinking, and have since become more accommodating of this fact; as long as one gets 8-ish hours of sleep, I shall be content.

On Jetlag

For every day you are in a different time zone, your suprachiasmatic nucleus can only readjust by about one hour.

Once again, I realized I cannot power through jetlag when I travel back home; it must run its course.

On Coffee

Caffeine has an average half-life of five to seven hours. Let’s say that you have a cup of coffee after your evening dinner, around 7:30 p.m. This means that by 1:30 a.m., 50 percent of that caffeine may still be active and circulating throughout your brain tissue. In other words, by 1:30 a.m., you’re only halfway to completing the job of cleansing your brain of the caffeine you drank after dinner.

For over 10 years I have been a coffee addict. I’d drink anything close to 2 to 3 16oz cups of coffee; before leaving for college/office, one post-lunch and one after coming back. Each cup was a necessity, without it, I’d feel drowsy, unfocused, and very rarely but surely, irritable. I’d then toss and turn in bed until 1 AM, and then wake up at 7, and continue this vicious cycle day after day. In the past 2 months, I’ve fixed this habit, and I must admit I feel much fresher and more energetic throughout the day, and sleep far more soundly at night.

On Weight Gain

The less you sleep, the more you are likely to eat.

short sleep (of the type that many adults in first-world countries commonly and routinely report) will increase hunger and appetite, compromise impulse control within the brain, increase food consumption (especially of high-calorie foods), decrease feelings of food satisfaction after eating, and prevent effective weight loss when dieting.

That explains my midnight snacking.

On Work and Learning

More than 80 percent of public high schools in the United States begin before 8:15 a.m. Almost 50 percent of those start before 7:20 a.m. School buses for a 7:20 a.m. start time usually begin picking up kids at around 5:45 a.m. As a result, some children and teenagers must wake up at 5:30 a.m., 5:15 a.m., or even earlier, and do so five days out of every seven, for years on end. This is lunacy.

Published in his seminal papers and book Genetic Studies of Genius, Terman found that no matter what the age, the longer a child slept, the more intellectually gifted they were.

On the Pride of Surviving on Short Sleep

Mother Nature spent millions of years implementing this essential physiological need. To think that bravado, willpower, or a few decades of experience can absolve you (a surgeon) of an evolutionarily ancient necessity is the type of hubris that, as we know from the evidence, costs lives.

The next time someone tells me “I don’t need sleep” or “I studied all night and I still feel fresh”, I shall point them to this quote.