Colleen: Knock. Knock.
Me: Who's there?
Colleen: Banana.
Me: Banana who?
Colleen: Orange.
This is a blissfully shortened version of the "Orange you glad I didn't say banana?" joke that is a plague to so many adults. Elizabeth is trying to teach her the real version on the sly and as I type Robert is sitting next to me demonstrating the full impact of the joke. Groan.