How about those who don't understand the up and down buttons?
1. The button is illuminated and people are standing there, but there is always someone who walks up, looks at the illuminated button, and pushes it again anyway, as if this will somehow speed up the elevators.
2. The elevator is full and everyone can't get on but someone keeps pushing the button before the full elevator has left, which means it sits there with the door constantly opening and closing.