Why We Sleep by UC Berkeley Professor and Google sleep scientist Matthew Walker is an interesting book. This book has single handedly showed me just how important sleep is (hint: it’s about 1,000x more important than most people think).
It is hard to summarise the main takeaways of a book packed with so many years of research, revelations and anecdotes.
Luckily I am not above trying to summarise the secrets of this book. So without any further pause here are some of the notes I took after reading this book:
- You can’t catch up on sleep, once it’s gone it is gone and damage has been done to you, similar to smoking, even when you quit you will have a higher risk of future health problems, even as the body recovers from quitting.
- Most people will never know their mental performance is impaired due to a lack of sleep because their brain is so badly impaired it can’t detect the degraded performance, it’s like being drunk and not knowing it. That is super scary thought indeed!
- Everyone has a natural circadian rhythm. Less than 50% of the population have an “early to riser” circadian rhythm. But our society is almost exclusively built around the lifestyles of these early risers leaving everyone else at a disadvantage. And no it’s not really possible to force your natural rhythm back to being an early riser. Researchers suspect we evolved to have different circadian rhythms for safety reason so that not every person in a tribe of people would be asleep at the same time.
- A large part of your future health problems are caused or made much worse by a lack of sleep, not sleeping and eating bad food can put you into a pre-diabetic state pretty quickly. Lack of sleep can worsen many already bad conditions such as Alzheimer’s and many heart problems.
- Most people skip the last 2-3 hours of their sleep cycle. Unfortunately this has the highest quantity of REM sleep REM sleep is so important for connecting new neural pathways, therefore losing REM sleep can really hold your learning and mental performance back.
- Why do we dream? Scientists don’t really agree on why we dream, but it may be because of memory consolidation and a way to sort out the cognitive load from the previous day. There does not appear to be a real pattern to dreams, nor can we truly control them or influence what happens in them (even if we think we can) they are more or less random spurts of memory mixed with other thoughts.
- Sleep length and quality changes across your lifespan but this is more of a problem than we think because our need for sleep doesn’t change as much as we think it does. Older people sleep less but they actually need the same amount of sleep as a normal adult. A dreaming state can help us solve puzzles subconsciously. For example, the periodic table was created after a particularly helpful dream that showed its creator Dmitri Mendeleev how he should organise the elements to fit together perfectly.
Without a doubt sleep has a lot of cognitive and health benefits. On the other side being sleep deprived is definitely insanely bad for you.
Though I think it’s important not to get wrapped up in all the doom and gloom. It would be better to focus on getting the right amount of sleep first and watch the benefits flow in.
Learn to love the process, not the final result.