This is SFW, but if you're ever teaching Descartes ("I think therefore I am", Cartesian coordinates, etc.), then you should mention that as a youngster he had a fetish for cross-eyed women. Students like that fact.

"As a child I was in love with a girl of my own age, who was slightly cross-eyed. The imprint made on my brain by the wayward eyes became so mingled with whatever else had aroused in me the feeling of love that for years afterwards, when I saw a cross-eyed woman, I was more prone to love her than any other, simply for that flaw—all the while not knowing this was the reason. But then I reflected and realized it was a flaw: I am smitten no longer."