I've long been fascinated with the origin of language, specifically colloquialisms that lose their original meaning but are still used in common speech. "Pop goes the weasel" is phrase that began as Cockney rhyming slag the meant "pawn the coat." It turns out that the cheery-sounding nursery rhyme is actually about being down on your luck, selling your clothes and going to the pub. Who knew?
If you're not so down on your luck, you can purchase a print here.