There was quite some 'I didn't know that!' in the book. What NREM and REM sleep do. What the consequences of deprivation are - both minute seeming (6 instead of the 7 to 8). How the brain develops over time (frontal cortex last, babies, kids and adolescents have vastly different schedules because of the development).

And of the things I did know, I learned the the background. Alcohol is a very good REM sleep precentor (and hence best avoided.at all cost). You really really need to sleep in order to learn. There's also a lot of repair going on from the brain damage ordinary day to day use is doing.

I was actually shocked how little I knew. Because of this book I have drastically changed my sleeping habits.

The writer has gotten some flak on two things (a yet unsupported claim lack of sleep causes dementia and the mention of a study with a woefully inadequate sample size), but that didn't detract from the rest of the book which seems to have solid backing and/ or medical consensus.

If you don't want to read this book, at least read the twelve tips for healthy sleep the American NIH has issued.