I was watching a couple episodes of Crash Course Psychology (yes, it's my hobby. Everyone has a weird hobby and mine just happens to be educational). And to quote Hank:
"The Information Processing theory proposes that our dreams help us sort out and process the day's events and fix them into our memories."
And YOU KNOW WHAT THAT MEANS?! It means that if we have a test or exam the next day, and after a whole day of studying we go to sleep, and I mean proper sleep with all the stages of sleep including REM where most dreams occur, we remember whatever we learn way better than when we don't get REM sleep.
So remember, sleep for at least 6 hours before a test or exam because REM lasts approximately 90 minutes, and including the other stages of sleep (NREM, NREM-1, NREM-2, NREM-3), we will probably need a few hours of sleep to help all the information sink into our memories in time for a test or exam.
Use this information wisely, my little karpoi peaches.
To Sleep, Perchance to Dream: Crash Course Psychology #9 - YouTube here's a link to the video I was watching