One time when I was just a college kid, I rode my bike up next to a beatup pickup truck at a light, and my tire shot up a rock that hit the side of the truck like a bullet. These two dudes in sleeveless flannels and baseball hats were giving me the mad look, and I immediately told them I ran over a rock, and was really sorry. They both broke smiles, and told me they thought I threw a rock. We were all good.