I'd say when other things attract my interest. I'm very much into the political season nowadays, spending quite a bit of time debating politics on other message boards, and haven't even visited this site in a while to even see what stories have been posted. This might even be my first post in weeks.
I've had a bit of an idea on stories but simply haven't had the time or inclination to get them down onto electronic paper.
Exhaustion is another factor that keeps me staring at a blank page for long periods of time before I give up and go to sleep.
