I toppled over at a stop sign once. As I approached it I wasn't sure if I should go across or wait for the car to pass. By the time I figured it out it was too late and I kind of panicked and just fell over. Embarrassing... The woman in the car behind looked so concerned and mouthed "are you okay?" I had to laugh it off.

I had been using clipless pedals for a few months before this happened though so it was pretty much a random, isolated event.

I use entry-level Shimanos, by the way...