hmm most recent one was just the other day when my rear wheel came off and jammed. I was doing the track stand (going 0MPH) and just toppled over to the side.

Second one was when I got carried away with yakking with my friends while waiting for the light to turn green. Again I was doing the track stand and just plum forgot that I was balancing on my bike. Took down several riders with me Such silliness so I laughed.

Third one is when the screws holding the cleats came loose and my shoe got stuck on the pedal.

Others I have no memories. But these were not because I couldn't unclip or forgot to unclip.