George: Do you realize in the entire history of Western civilization no one has successfully accomplished the roommate switch? In the Middle Ages you could get locked up for even suggesting it!
Jerry: They didn't have roommates in the Middle Ages.
George: How do you know?
Jerry: Well, for one thing, they didn't have apartments.
George: Well, I'm sure at some point between the years 800 and 1200 somewhere, there were two women living together.