When play becomes work

I like work; it fascinates me. I can sit and look at it for hours.
-- Jerome K Jeorome

We've all heard of situations (and have probably even experienced them ourselves) where someone liked their work so much that it was almost like play. Well, the reverse happened to me recently: I was working on my entry for the Intel Threading Challenge, and I was nearing the contest deadline, with my entry still missing the key bits of the algorithm. I was almost at the point where I thought I'd put in as much time as it took -- even if it meant staying up half the night -- and finish the damn thing, when it suddenly hit me: I'm supposed to be enjoying this; I'm working on this in my spare time, after all. I switched off the computer, and next morning, well past the deadline, when I thought I'd experience a pang of guilt at missing the submission, all I experienced was the thought of hacking together the code at my own pace, enjoying myself, and well, having fun.