hijack back
One night I was about to fall sleep, when I heard someone laughing, so I woke up again and wondered who had laughed. The conclusion is I was laughing when I was about to fall asleep for an unknown reason
Another case. For about a week, I always woke up at 3:15 in the morning EVERY NIGHT. That scared the hell out of me, because I strongly believe that 3:15 is the time when all unseen creatures start to wonder around.
Anyway, I heard a theory about the REM cycle, basically you have four hours for a complete REM cycle, and this goes like, light sleep - deep sleep - light sleep - awake. That's why a recommended sleep is for eight hours, within two cycles. So if you have to do late night study and only have five hours to sleep, better kill an hour: instead of five, you should get four hours of sleep in order to fully awake the next day and do good on your exams.
Just my .02 cents
edited for REM instead of RAM
REM = Rapid Eye Movement
Thanks, decadence! Tee-hee