[chjj]

No deadline. I just have a tendency towards obsession when I'm working on a project I'm very interested in. I tend to get into a kind of manic phase where I can't sleep even if I wanted to. There's no real telling when that phase will end. So I end up coding for an unhealthy amount of time. I don't recommend it to anyone.

[HappySweeney]

I have the same thing, self-diagnosed as monomania. I had to train myself to stop thinking about my obsession when not at it, and the condition eventually subsided enough that it doesn't completely screw up my life anymore.

nb: looking it up on wikipedia, it seems that monomania was a 19th century psychiatric diagnosis, and is no longer considered a real condition.