Have you ever had a car on your tail anxious to pass, and when they do pass you catch up to them at a stop light? The lane you are in moves fast and you get through while the tailgater gets stuck with the light. As you continue, that same car catches up to you again and hangs on your tail. In frustration, you turn on your headlights and that lights up the tail lights. (That is a trick my father used). As the tail gaiter hits the breaks, you step on the gas. When he finally catches up to you again and passes, he gives you a wave. You feel sorry for him that he is handicapped and has only one finger on his hand. He again gets behind you by being in the wrong lane at another traffic light. You are approaching a reduced Speed Limit area and you slow down and he speeds past you. You pass again when you find him stopped by the Police. You wave to him. So as not to make him feel bad for having lost the use of four fingers, you show him that you are sympathetic and give him a wave using just one finger.