I went to a startup weekend maybe 9-10 years ago. It was a lot of fun. I didn't pick the best idea to work on, just the funnest sounding. Ended up with a small team (3 of us total) and we we're one of the only ones to actually have a good demo. I try to do some kind of hackfest every year now.

There is just something magical about working on something fun and pulling an all nighter.