But bra-less large-breasted girls' school physical education? This I do not believe.
I think that it's a reference to a story that Sylvester Stallone used to tell about how he dodged the Vietnam draft by teaching phys ed at a Swiss girls' school. (He changed his story around the time that Rambo came out, saying that he was 4F because of some vague medical condition. He did attend the American College of Switzerland for a few years, but dropped out before graduation.)