Jake and Joe are in prison, in separate cells, some distance away from each other. Sad little jail cells really, with only a solitary, tiny window to peek into the outside. So they pass the time as best they can by telling each other jokes.
One day, Jake asks, "Got any new jokes, Joe?"
"Sorry," Joe says. "I told you every joke I know months ago. You got any more new jokes?"
Jake thinks for a moment and says, "Well... I do have one more joke. But it's one of those jokes you gotta write down. It's not funny when you say it out loud. Gotta draw a picture and stuff."
Joe suggests, "Why don't write it on a piece of paper, and throw it over here?"
Jake agrees, and spends all week collecting the perfect materials, rewriting the perfect joke, drawing the perfect accommodating picture, and shaping that joke into a perfectly aerodynamic and balanced paper plane.
On Friday evening, when the lights go out, and the guards are changing shifts, Jake tells Joe, "Okay! Here comes the joke!"
He tosses the paper plane, it sails across the prison hallway, slips between the prison cell bars, and glides directly towards Joe's awaiting hands.
Just as Joe is about to grab the paper plane, it gets caught in an updraft. It bounces again the ceiling, and then glides out the tiny cell window.
"Did you get the joke?" Jake asks.