Staying up to late w/ no reason

3AM is my usual bedtime, but if I'm really wrapped up in stuff, I can push it to 5AM without even trying. What sort of stuff keeps me up? Playing games, watching movies, trying to decide on a game to play or film to watch, browsing online and downloading stuff, re-reading VG magazines from the mid-90s, randomly organizing things on my computer...things like that.
I'm a compulsive time-waster, particularly at night, and always hate myself in retrospect since while I'm at work I'm thinking, "I should've done this; why didn't I do that; next time I'll get to that other thing..."
Don't really know what to do about it, actually.

Jam it back in, in the dark.