>>106697816your body unconsciously looks for stimuli that indicate time and creates melatonin in response that eventually builds up and makes you sleepy, then when you sit still for a while (15 minutes on average) part of your brain assumes you have fallen asleep and triggers your muscles to test you, then if you still don't move, it begins to paralyze you (you are usually asleep by this point, but if not this becomes sleep paralysis). you go through 90-minute cycles going deeper into sleep stages where you are harder to awaken (leaving you very groggy if you wake by alarm) and then back out again into light sleep (REM or rapid eye movement) which is where you dream. this lighter sleep in-between cycles increases in length the more cycles you go through in a row and you miss out a lot of it if your sleep is frequently interrupted, though it's the time when it's easiest to awaken and feel properly refreshed. the less REM sleep you get, the more shitty you will feel and when in sufficient debt you will randomly fall into what are called "microsleeps" where you momentarily pass out any time you're sitting still. if you're low on REM time, your body will start to increase the amount of time it spends in REM sleep per cycle, which has a bunch of negative effects and gives you that uncomfortable dissociated feeling when you wake up. the exact time your brain targets for sleep is genetic and different between individuals which allows human communities to always have someone awake, although if you never see the sun you will never unconsciously see the outside light color change or get darker so you won't get any melatonin anyway. taking melatonin supplements will unfortunately also make your brain stop producing it which can leave you in even worse shape than before you took it.
