I decided to read Dr. Matthew Walker’s Why We Sleep for two reasons: 1) to continue stretching beyond my comfort zone and exploring science writing and 2) to see what it had to say about the relationship between trauma and sleep. While I rarely remember my dreams, it turns out I twitch a lot in my sleep, disturbed. Sometimes, I wake up in the middle of the night with my mind racing and my feet clenched. What work is happening in my sleep, I wondered.

It turns out the body processes memories during sleep. During sleep, the brain processes and organizes new memories. The first evening of sleep after learning information is the most important night for retaining that information. So if you study for a test two days before the exam, but get bad sleep the night after you studied, you won’t retain the information as well as if you had gotten good rest. You can’t “catch up” on sleep later. When it comes to learning, sleep is an all-or-nothing game. Dr. Walker’s writing also suggests that REM sleep is important for processing memories, taking the sting out of traumatic memories and retaining the wisdom in them.

The book does a convincing job arguing that sleep is an undervalued and crucial part of our health. While many people know we’re supposed to get eight hours of sleep, it’s revealing to read how much we lose when we give up a night of rest. A lack of sleep shoots down your work productivity. It leads to dementia, cancer, heart disease, among other health issues. It even increases your appetite, making you more likely to munch, nibble, and gorge throughout your day.

The book includes damning critiques of the United States’ school system, the US military’s use of sleep deprivation as a form of torture, and the medical school residency requirements. We senselessly deprive adolescents of the proper amount of sleep, and we’ve known it for decades now. Waking adolescents up at 7am for school is the equivalent of waking adults up at 4 or 5 am. It’s incredibly frustrating the United States keeps sticking to archaic systems like early bird school schedules and inches, feet, and so forth. When it comes to sleep deprivation, Dr. Walker convincingly argues that it’s a form of torture, ineffective in drawing reliable information from suspects. Perhaps most insanely, when it comes to med schools, Dr. Walker relates how the person who designed residencies for med students was literally addicted to cocaine and built an absurd system that robs many med students of proper sleep, literally causing deaths through medical mistakes. Our body has spent millions of year optimizing its sleep patterns, Dr. Walker argues. It is ill-advised to attempt to break out of our bodies natural rhythms.

The book includes excellent tips for getting better sleep, some of which you’ve probably heard before: stick to a consistent sleep schedule, even on weekends, don’t drink caffeine in the afternoon, don’t exercise before bed, don’t look at electronics before bed. Others are more surprising: 1) heavily drinking alcohol robs you of REM sleep and might mess with your breathing at night.

The book was cleanly and thoroughly executed, although not all the information was incredibly engaging. I recommend the book for anyone interested in neuroscience or sleep.