What’s the difference between 9/11 and a cow?

The right-wing doesn’t know how to milk a cow.

Knock Knock. Who’s There? 9/11…

Knock, knock
Who’s there?

9/11
9/11 who?
…you said you’d never forget…

Here’s another 9/11 joke: Why’d the 9/11 conspiracy theorist quit her job?