...crash my bike during a race.
I managed to hit a deep rut left by the motorcross races that take place on the same track. Usually you have to time them, and sail through them without pedaling as they're deep enough to let you through, but too deep for you to spin your pedals while going through. I hit this one at an angle, which jerked my front wheel very suddenly 45 degrees to the left. Whoopsie-daisy-owl!
I totally rolled on the bike while clipped into my pedals. I was also fairly certain there was a bike right behind me, ready to run into me. Somehow during the ensuing scramble to not die and then get back up my chain came off. In the time it took me to shift it back onto my chainring, I went from middle of the pack and gaining places to DFL. (A Technical term: Dead fuck*ng Last)
I rode hard afterward, and while being alone for a good portion, I caught the tail of the race and finished ahead of 4 or 5 people.
Not an awesome finish, but I feel pretty awesome about what I did with a really shit situation.