The line comes from Seinfeld, spoken by George Costanza in the 1994 episode The Hamptons, after he is seen naked following a swim and tries to explain away shrinkage to Jerry's girlfriend. The scene became one of the show's most quoted moments, helped by syndication and later by short clips shared on social media and soundboards. It endures because the excuse is instantly recognisable, endlessly reusable for any embarrassing reveal, and funny even without knowing the full plot.