That's a well-known story, especially if you worked on cruise ships and you talk to the british shop keepers. They love it when Americans walk in and ask for a fanny pack. IN Britain the fanny is not the part in back, either (sorry to any Brits who may be reading thism but it isn't a bad word here).
But then again, here a "shag" is a haircut from 80s and a over there a "fag" is a cigarette.