Once upon a time, a mathematics professor (whom I shall call Professor M) from a North American university was regaling a small group of professors and graduate students with some anecdotes concerning a psychology professor (whom I shall call Professor P) and a mysterious black dog (whom I shall call B).
A that time, the mathematics and psychology departments of this university shared a floor of a large, multi-storey building, and they used the same elevator to ascend to work each morning. For some time, a black dog seemed to accompany Professor P to work each morning. But nobody in the mathematics department was quite sure, because although they seemed to come upstairs in the same elevator, Professor P did not seem to give any attention to B, the black dog. Being shy by nature, and because the dog did not seem to cause any trouble, the members of the mathematics department tolerated the presence of B.
Professor M continued with his story, which included a number of very humorous anecdotes about Professor P and some shenanigans that B created, none of which I still remember. Then, after a pause, Professor M solidified his reputation for self-deprecating humour by stating:
I’m so happy that we share a floor with the psychologists … they’re the only people on campus that make us look normal.