I used to sleep from 9:30 PM to 7:30 AM when I was in High School and I never had to study a single bit. I just remembered what I was taught in class without any trouble and aced most of my classes.
When I reached college, I got a late night job and started to sleep from 4 to 6 hours a day for about 2 years. My grades dropped badly; I couldn't remember what I was hearing in classes, I wasn't able to stay focus for as long and I ended up failing classes on my last semester.
It's probably the things that I fear the most from the lack of sleep, not being able to use my brain efficiently when I'm awake.
I remember reading about the fact that the first few hours of sleep are mostly there to physically rebuild the body, while the last hours of sleep are helping mostly with the memory. I don't have sources and considering the current article, I doubt it's as definite as what I read a while ago but might be interesting to read about more extensively.
When I reached college, I got a late night job and started to sleep from 4 to 6 hours a day for about 2 years. My grades dropped badly; I couldn't remember what I was hearing in classes, I wasn't able to stay focus for as long and I ended up failing classes on my last semester.
It's probably the things that I fear the most from the lack of sleep, not being able to use my brain efficiently when I'm awake.
I remember reading about the fact that the first few hours of sleep are mostly there to physically rebuild the body, while the last hours of sleep are helping mostly with the memory. I don't have sources and considering the current article, I doubt it's as definite as what I read a while ago but might be interesting to read about more extensively.