Book review: Why We Sleep

I always wondered what was wrong with me, why I needed to sleep 8 hours a day, why less than that would make me insufferable, on edge and less productive that I’d like. And then I found this book.

And it seems I’m normal.


One of my friends, when sh started reading the book told me it was a scientific praise of sleep. I agree. The book is a demonstration of, well, why we sleep, and also why we should sleep.

The book is split in four part, each of them consisting of several chapters. This review will focus on each part, as they make consistent blocks.

The first part tackles the physiology of sleep. What happens when we sleep, how does the brain work and also the evolution behind sleep. What are the effect of the substances we inject ourselves to keep being awake (or to sleep)? Are they allowing to function as if we slept? The most fascinating take here was how sleep was generated and how this generation evolved with age. It was also fascinating to learn that several dementia diseases actually started where sleep is generated!

The second chapter is about the reasons to sleep. At least that’s what it is called, I think part 3 is also a good list of reasons to sleep! but I digress, back to part 2. “I’ll sleep when I die”. This expression is quoted several time sin this part, and it is there to show that no sleeping makes the conditional happen far sooner… I didn’t know that even waking up with an alarm clock actually jolted the heart and could lead to a heart attack. I’m not even talking about daylight saving, where studies statically showed that more people died! This is crazy as we talk about the “precaution principle” so often about everything, except when we do have proof! Amazing of carelessness.

There are many other benefits of sleep, let’s say on the spirit and soul aspects of life. So many movies, for instance, about PTSD when it seems that sleep can actually help so much is addressing psychological trauma. When I started reading the chapter, Walker talks on that aspect about the fact that sleep helps distantiate oneself from horrible events, which sounded odd at first. Because of course, it feels like being less and less sensitive to horrors and life hurts. But there is a balance, as always. The philosophic “such is life”, where we accept that, yes, such is life. It brings pain, it brings joy. So sleep allows people to feel again, by processing the extreme feelings and allowing them to subside. I also liked the numerous studies on the impact of sleep on memory, creativity, and I hope this is the reason why I can tackle so many things at the same time, reading, writing music, code…

The last part addresses the modern society impact on sleep. I saw actually one of my colleagues yesterday, he started wearing glasses that filter blue light. He doesn’t have glasses otherwise, it’s just for a better sleep at night. I don’t know if he read this book or not, but yes, that’s a sensible advice when you look at the data. Same for sleeping pills. I read an article in the Guardian yesterday about a new therapy to help people sleep better. No pills, an actual cognitive behavioural therapy. Of course, I was very sensible to the first chapter there, as it talks about the devastating lack of sleep on people driving. I don’t subscribe to his qualification of almost crime for people in a crash due to a lack of sleep, for personal reasons. I do think that this reason should be advertised, but I don’t think it can be criminalized, as the book itself shows that there can be many reasons for a bad sleep quality (one of them being or societal pressure), and it is not always obvious to get a good night of sleep, even if we do everything right (genes perhaps? I don’t know, I don’t want to find a pretense, but there are cases where lack of vigilance at 2pm is not because you partied like crazy or are drunk all the time).


Mental health is a critical problem today, but just like climate change, what we don’t do today will only impact our future, what we feel today is only a premise of what’s to come.

Unfortunately, it’s still fancy to not sleep enough, despite the evidence that it is bad for your health. We still think we miss on life when we don’t enjoy every second of our “young” life. But we are wrong. Mens sana in corpore sane.

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