Buzzy knows this obvious, but now it's supported by science. Scientists have determined that when you're sleepy -- or sleep deprived -- the part of your brain that craves anticipation and reward is much more active than the rest of the brain. In addition, the part of the brain that learns lessons from mistakes isn't working very well. So you get pulled into bets that you wouldn't ordinarily make. Fascinating story.
http://www.msnbc.msn.com/id/18561132/