Mid '80s, Centurion Ironman (red/white), trying out the Shimano (IIRC) copy of the Look clipless pedals for the first time. Rode out of the bike shop parking lot onto a road paralleling the Interstate and had gone about a block when some a-hole in a car cut me off. As I hard braked to a stop so's I could continue cussing him out...yep forgot to unclip, fell over and he drove away laughing. Luckily I was at the side of the road and landed in the grass.