The one where my brother got confused with the difference between a straight razor and a disposable razor...
Jordan: "I want to start shaving with a straight razor."
Me: "Really? Those can be really dangerous."
Jordan: "What are you talking about? To who?"
Me: "Most inexperienced people. Like in that musical where Johnny Depp was a barber and murdered people with a straight razor. It's a weapon."
Jordan: "Listen sweetheart, those were called scissors."
Also, the one where my brother got confused with the difference between Sweeney Todd and Edward Scissorhands.