I know, quite possibly one of the stupidest things anyone has ever done. I rode into the back of a parked car. Clipping along anywhere between 18 and 23mph with cars passing by my left, I turned my head over my left shoulder, turn back and down to check my computer and wham. dead stop, with head hitting back of car. Lots of rib and arm pain. Tell me Im not the only one to do this?? please.