Here's mine. Knock knock. Who's there 911. 911 who You said you'd never forget
OMG my neighbours cat is stuck on the roof-" 911: Ma'am, this is an emergency only service- "-of my sons mouth."
9/11
the nine-elephant
A: Elephants never forget.
Cause she's got no arms. Knock Knock. Who's there? Not Sally.
A: Because she has no arms! Knock knock. Who's there Not Susie!
I go to the tallest tower in my city. Call up a pizza place and order two large planes.
because he was in the middle of 9-11! Better phrasing recommendations appreciated :-)