Can you think of other examples where Christopher doesn't understand what is happening but the audience does and we think it is funny?

When Christopher says, "I cannot tell jokes because I do not understand them," jokes become funny by not being seen as jokes.

When Christopher arrives in London, he asks the shopkeeper for directions to his mother's flat. The shopkeeper tells him to buy an A-Z.

And I said, "Is that the A to Z?" and I pointed at the book.

And he said, "No, it's a sodding crocodile." (Christopher does not understand sarcasm).

And I said, "Is that the A to Z?" because it wasn't a crocodile and I thought I had heard wrongly because of his accent.

And he said, "Yes, it's the A to Z."