Lexicon. Mild reworking of a Monty Python sketch involving John Cleese playing Anne Elk, (Miss). YouTube doesn’t seem to have the original, only performances later, which don’t appear to have the right phrasing. This implies it was being improvised, within certain limits. Here’s Miss Elk announcing a new theory:

This can be rephrased in all kinds of ways. “My drink, which is mine…”, “My car, which is mine…”, etc.