The Two Types of Sleep
Why do we sleep?
If your answer to my question was “Because we’re sleepy,” I suggest you pay more attention to the quality and length of your sleep, ’cause you’re probably suffering from the lack of REM sleep.
I’m talking about Rapid Eye Movement (REM) sleep, the type of sleep that improves creativity. The sleep that brings you dreams, from your nightmare, passionate fantasy, to the strangest dream could ever be. Some people believe that dreams are (sometimes) premonition — a sign, a metaphor for upcoming fate, they would say. But that theory is unproven since dreams are (as science has shown us) merely products of your brain trying to connect (almost) random neurons in your brain, hence, the bizarre dreams were made.
I say ‘almost’, because if there’s something still active during this time of REM sleep, that would be the part of your brain that regulates emotional state. So there’s a high chance that you would dream about the object of your affection, or your work anxiety during this time. If there’s a premonition in your dreams, that would be the emotional state that maybe you could not verbalize in your real life, but your brain reflects it at slumber. This is why psychotherapist asks their patient to make a note about their dreams.
And there’s also NREM (Non-Rapid Eye Movement) sleep, this one doesn’t come with a plot. It’s the time when your brain stores short-term memories into the long-term one. This is important, especially if you’re in the middle of learning something. So if you’re a student, looking for the most efficient way to memorize everything for your near assessment at school, science suggests you put a good 9-hour quality sleep between your learning sessions.

How We Perceive Sleep
Sleep is so vital to us, humans (and to many species other than us). So important that it is predicted that the reason why our brains evolve so much, faster than our fellow simians, is because what our brains do when we are sleeping (the whole memory-storing and creativity-improvising thing).
There are so many things going during our sleep, not just the NREM and REM sleep, but also brain and body detox. For every sleep we are losing, every quality sleep we are compromising, cells are dying away for nothing. You could not ‘pay over’ your sleep ‘debt’. Damage has been done. Life (hopefully) goes on, your body will continue to regulate according to its biology clock.
It’s proven that the lack of sleep accelerates aging, it’s also predicted to be one of the causes (and symptoms) of Dementia/Alzheimer, and cancer, and many unwanted health conditions. Sleep can’t promise you eternal life (not for now), but it could give you the fitness and vitality you need to maintain a great and active life.
Considering its crucial benefits, it’s funny how people perceive sleeping as something puny, something unuseful. Lack of sleep is applauded in a certain country in Asia — if you are caught sleeping during the work hours in this country, your colleagues & boss are supposed to adore your ‘hard-worker’ trait. Many thinkers, political leaders, business owners are categorized as short-sleepers — they don’t need that much sleep, 5 hours a night is considered too much for them!
Another thing we should put in mind is how different is the need to sleep (hours, time) for different people of varying age and genetic. Some are early birds, they sleep earlier and wake up once the sun rises. Some are night owls, they sleep later at midnight and wake up in the afternoon. Still, these people need to sleep according to human’s circadian clock (at night) and an optimum of 9 hours per day.
A child needs more sleep than adults. Adolescents experience a change of sleep time during puberty. There are many variations to sleep requirements, but all of these specific needs are being compromised every day due to public agreement on school and business hours.
It was clear that people need to learn more about their sleep and how to attain an optimum, qualified sleep, every night. This book, Why We Sleep by Matthew Walker tells us all we need to know about sleep, from what our brain does when we are sleeping, what chronic lack of sleep would do to a person, what caffeine and sleeping pills do to us, and one of the most interesting things I found in this book: the philosophical and evolution discussion about sleep.
Why did life ever bother to wake up?
Why We Sleep by Matthew Walker, PhD.
Sleep: Still a Mystery to All of Us
All of our lives as a human, we are told that we are all about making sure our genes remain in this vast universe.
We procreate, we protect our offsprings, we run for our lives, we search for food, we raise plants and animals (so we could use them to produce our food, or we could eat them). All of these are things we can not do while we are sleeping.
So, why are we sleeping? Why evolution put us in such a dangerous situation?
So one of the theories said that we are sleeping to fix all things broken and degraded because of us waking up. The detox thing, the NREM and REM cycles.
If that’s true, here’s the next question: if waking up is that much destructive to our body, that we need sleep to repair everything in order for us to stay alive,
Why did life ever bother to wake up?