I was trying to convince some of my students (5-6 years old) that I have a pet dinosaur. It made sense in the context of the lesson, just go with it. Anyway, they all kept saying that I couldn't possibly have a dinosaur for a pet, to which I would respond in a bewildered way, "But why not?"
Eventually one little girl cried out, "Don't be silly, Teacher! Dinosaurs aren't alive! They only live at Universal Studios, and they're made of robots!"