Three absent-minded professors were talking together in a bus terminal. They got so engrossed in what they were saying that they didn’t notice the bus had pulled in.
As the driver sang out, "All aboard," they looked up startled and dashed from the platform. Two of them managed to hop on the bus, but the third didn’t make it.
As he stood sadly watching the bus disappear into the distance, a stranger tried to cheer him up, saying, "You shouldn’t feel too bad. Two out of three made it, and that’s a pretty good average."
The professor shook his head. "But THEY came to see ME off."