Joe tells a joke.

I’m sitting at my desk and Joe walks in, holding a piece of plastic rollercoaster, his mouth wide open.

Joe: “Mama, this is a joke.”

Me: “What’s a joke?”

Joe: “It’s funny!”

Me: “It IS funny. But, I don’t think I get it. What’s the joke?”

Joe, showing me the bit of rollercoaster and opening his mouth wide again: “This!”

Me: “Okay, but what’s the joke?”

Joe: “You yaff! Cos it’s funny!”

Me: “But what’s funny about it?”

Joe: “THE JOKE!”

Hilarious.