I was watching NYPD Blue and one of the detectives was bothered by the fact that he sang "Pop Goes the Weasel" to his child but had no idea what it meant. It became sort of a running gag and they asked everyone they met what the song meant. In the last scene they sort of resolved it with a fax from the library saying there were many possible interpretations. But they didn't disclose any of them.

I knew Mudcat would have the answer.