What is your motivation for joining LDs or jams in general?

I'm kinda curious what motivates people join these. (Partly prompted by my own resolve to join despite a Splatfest being held on the same weekend and 5 hours of work eating a chunk of Friday's hours. Next weekend promises to be brutal.)

Do you aim for top rankings? Exploring ideas outside of the doldrums of work? Learning? The intrinsic thrill of rushing against a deadline?

For me, it's rushing a deadline. To say I completed a project - not necessarily a good one - but completed by the strictest deadline. LD50 was partly written while at an Italian restaurant with "a laptop that looks like its 50 years old" according to the kids present.