For about 6 years now I've had a running gag with one of my cousins where, once every like 6 months or so, I'll find a way to insert a certain mental image into the conversation. The mental image is "a pile of toilets in an elevator, which closes and then goes up." I do this as naturally as possible. I'll construct an entire scripted conversation path with the express intention of leading into an opportunity for me to say "a pile of toilets in an elevator, which closes and then goes up." I have talked other people who aren't me into integrating the phrase into their conversations with him just once. He fucking hates it. He has threatened to kill me about it. I let so much time pass between instances that he never sees it coming. Because he knows that the only way to see it coming is to integrate into his brain the expectation that at any point, any conversation may suddenly turn out to be a toilet-elevator trap. And that's a fucking insane way to live.