I'm jealous. 4-6 hours of sleep is a good night for me, punctuated at least once or twice a week with days I never actually get to sleep; I just sort of lay there in bed from midnight until the sun comes up again, maybe drifting to a weird loopy half-conscious state for brief periods. The only things that can bring my sleep schedule in line with "normal" amounts is if I do hard physical labor for 8-12 hours during the day, have sex, or drink about two beers and read for a half hour before bed. Basically this has persisted my entire life - growing up I'd read half a dozen books a week at night when I was supposed to be in bed and couldn't fall asleep.

On those nights when sleep just isn't going to come, I've given up on trying; I'll just go find something to do. All-night programming is a pretty good fit, although I've also spent entire nights painting and putting down flooring, or tinkering in my shop.