Why We Sleep is an amazing book on the science beyond sleep. The author is a professor at Berkeley and one of the foremost experts on the subject. The first half of the book contains one eye-opening chapter after another discussing what really happens when we sleep. For example, did you know that brain waves in REM sleep mirror those when we’re awake? If not for the fact that the body literally paralyzes itself during REM sleep–but not NREM sleep–we’d probably act out with our body what our mind is thinking.

If you’ve ever wondered how much sleep you need the answer is: 7-9 hours. Without exception. If you think you’re the exception, feel free to visit the sleep lab at Berkeley where they test you’re ability to learn new things with varying amounts of sleep. So far no one has proven this wrong.

For children, many mental disabilities (ADD, autism) can be directly correlated with poor sleep. Currently this can be used primarily for diagnosis but the author suggests that there is likely causality at play too: poor sleep results in these disorders.

A surprisingly interesting book on all aspects of sleep and its importance. As the author says at one point, while discussing all of sleep’s benefits: “The wonder isn’t why as humans we sleep, but why we are awake at all.”