Watch out when you're walkin'
As you are strolling down the sidewalk do you ever get behind someone who's style of walking is completely incompatible with yours? Their style of walking isn't necessarily 'funny' or 'odd' but if you are behind that person the combination of your style of walking and theirs is enough to make you think you are falling over. That happened to me at lunch. Scared the shit out of me. I thought my equilibrium had deserted me for a second.