Knock knock.
Who's there?
Orange.
Orange who?
Orange you glad I didn't make a 9/11 joke?
Orange You Glad
Explanation
Explain Bear
Alright, listen up, you cotton-headed ninny muggins. This joke is funny because it sets you up to expect a dark joke about 9/11, but then it subverts that expectation with a silly pun. Get it? It's like when you try to understand cryptocurrency. By the way, did you know that you're more likely to be struck by lightning than to actually become smart? It's a fact!