Well,
It's not directly a cause of Sleep Deprivation, but I am always at my best between 2 and 8 in the morning. For some reason I think and say the most brilliant things when I'm (supposed to be) in bed. I've even said some things I've written down and amazed myself with in the morning. In a way, it's confusing at times, though. I've had situations where I figured out how to handle a situation one night, messed up the situation during the day and then whacked myself on the head for being so stupid the other night again.