Why We Sleep: Unlocking the Power of Sleep and Dreams by Matthew Walker
My Rating:
This is certainly one of the most interesting and impactful books I have read so far. I have seen a lot of books (not mentioning any of them here) and people (not mentioning anyone either) preaching that we need as little as 4 hours of sleep in a day. Some said that sleep is just a habit and we can create a habit of sleeping lesser by practicing just like creating any other habit. None of them actually gave any scientific evidence on what actually happens when we sleep less. This book is presenting the state of research on sleep and why we actually sleep.
What it contains?
If you are still not planning to read the book after this review, the major takeaway of the book is that you must get good quality sleep for at least 8 hours every day. It is important to note the term “good quality” here. The author mentions several times that it is important to work towards maintaining a good quality of sleep to reap maximum benefits from our daily slumber.
The books contains 4 parts and some of the points I find interesting:
Part 1: This Thing Called Sleep
- Sleep improves the function of every part of our body
- Sleep timings and when we feel active depends on our internal clock called the circadian rhythm and a chemical in our brain called histamine.
- Caffeine disrupts our sleep and usually takes more than 8 hours to completely flush out. Partial caffeine will degrade the quality of sleep.
- The amount of NREM sleep (including light and deep sleep) is higher early in the night and the amount of REM sleep is higher in the late-night (early morning) sleep.
- Our sleep (mainly because of change in the natural circadian rhythm) changes throughout life. Teenagers usually have delayed circadian rhythm and must wake up later than adults to get the benefits of sleep.
- The brain is mostly developed during REM sleep. For the same reason, toddlers have a very high amount of REM sleep.
Part 2: Why should you sleep?
- Sleep aids learning. It is during sleep, our memories are moved from the temporary location in our brain to the permanent storage
- Sleep aids creativity. Our creativity improves with new connections in our brain and new connections are created during REM sleep.
- Lack of sleep weakens the immune system. In cases of Fatal Familial Insomnia, the lack of sleep weakens the immune system which becomes the cause of death
Part 3: How and why we dream?
- We dream mostly during REM sleep.
- Our creativity and ability to find patterns increases with REM sleep.
- Our body is paralyzed during the dreaming state so that we don’t act on our dreams.
- Dreaming provides the emotional cleansing. Dreaming helps us to remove emotions from the different events in our life which would otherwise trouble us.
Part 4: From sleeping pills to society transformed
- Factors impacting our sleep include the use of electronic devices, exposure to high-intensity light in evening hours, caffeine, alcohol, high temperatures, etc.
- None of the sleeping pills actually help with sleep. The sleep produced after taking sleeping pills do not show the benefits of regular sleep and are highly addictive.
- Early starting schools are killing the brain development in teenagers by depriving them of the necessary early morning REM sleep.
The good
I find the book very interesting and every single statement is accompanied by reasons and in some cases, details of the experiment performed by researchers which lead to the given conclusion. The author did make me realize the importance of prioritizing sleep over anything else. You will learn a lot about sleep and everything is written in a simple and accessible language.
The bad
I couldn’t find anything bad about this book. I believe this book is a must-read for everyone.
Final words
Go ahead! You can’t be wrong about reading this book. The author has put every effort to make the book as simple and practical as possible. You will learn a lot about what could be wrong with your sleep and what needs to be done about it. The book would surely need updates in the upcoming time when new discoveries emerge about why we sleep.
I am not sure whether the case “Dreaming provides the emotional cleansing.” is full-proof. I have had troubles with my dreams and sometimes they were about my unfulfilled desires.
Additionally, waking up at 5 AM serves as a great day-starter and I have seen folks who are highly productive waling up early. So does this contradict ti the fact stated in the book or do these people simply just get more things done because they have more time at their disposal??
About the emotional cleansing part. Normally, if we go through some experience like some near-death experience or some terrifying experience, we might see the event in our dreams, and eventually, with time, the emotions start to fade away. You don’t feel the emotion you felt when the event actually happened every time you think about the event. And some people who are unable to get REM sleep are actually having the same trouble. They feel the emotion with the same strength every time they think about it.
And about the unfulfilled desires, sometimes people do claim about what the dreams mean but scientifically there has not been any pattern found so far. Some people are able to even control what happens in their dream (lucid dreaming) which has been verified to be true via experiments.
Waking up at 5 am is good if you do it every day and get enough sleep which means sleeping early as well. In general, following a routine will increase productivity by keeping the circadian rhythm in sync with our actions.
And specifically for teenagers, as part of human development, more sleep is required to build connections in the brain (happens in REM sleep).