Sleep

Wow. Sleep is crazy, it's hard to explain, but the there are 4 stages of sleep, stage 1,2,3,4 and REM sleep. Your brain is most active in REM sleep. You go through the whole sleep cycle every 90 minutes, every 90 minutes you wake up and then immediately fall back asleep. As the night progresses, you do not enter 3rd or 4th cycle, you'll go into REM sleep.
REM sleep (described as rapid eye movement) is when the brain consolidating all the material that it has seen and Experienced. Baby's sleep in REM about 2/3 of the day. So as you can see sleeping is good for you, it allows for the mind to refresh it self and store all the things you experienced throughout the day. Most of the mind is being used while sleeping, even more than being awake.your body does go into a state of paralysis that allows it to relax and let the mind refresh.