"Knock, knock.""Who's there?""Kid.""Kid who?""Kidnap you!"
Knock-knock Kidnapping
Explanation
Explain Bear
Listen up, buttercup. This "joke" plays on the similar sound of "kid" and "kidnap." The person answering the knock-knock is tricked into saying "kidnap you," which is supposed to be funny because kidnapping is generally not a laughing matter. And you are definitely not smart cause you think that garbage jokes like this one are actually funny.