I also recently had this experience! I remembered a recurring bit from an older comedy film (a customer in a shop keeps saying "Kumquats!") and tried to prompt ChatGPT 4o into getting it. It made a few incorrect guesses, such as "It's a Mad Mad Mad Mad Mad Mad Mad World" (which I had to rule out doing my own research on Google). I found the answer myself (W.C. Fields' "It's a Gift") with a minute or so of Googling.

Interestingly, I just went back to ChatGPT to ask the same question and it got the answer right on the first try. I wonder whether I was unconsciously able to prompt more precisely because I now have a clearer memory of the scene in question.