Why, why, why???

Why do I do this to myself? I finally have a night where I can get some sleep, and what do I do? I sit at my laptop for three hours programming a toggling target lock mechanism for the game that I'm making. Yes, it looks pretty damn cool and makes me happy... but now it's 3 am! And I need to get up at like 9 to go to a day full of classes... I shoulda just gone to sleep... damnit, damnit, damnit.... -_-