Because sometimes I have days like today where I fall asleep at 4:30 in the afternoon, wake up at 6:30 to eat dinner, then promptly go right back to bed, and then wake up at 3 am and decide I need to take a shower so I don't have to do it in the morning. Because I have breakfast with a friend at 8:30 and absolutely plan on going back to sleep after I blow dry my hair. Because somehow, I can still be tired after all of that.
Sigh. I guess sometimes your body just revolts and informs you that IT REALLY NEEDS SLEEP by making you utterly incapable of staying awake during normal hours.