If ever you want to annoy someone who annoys you, just say this punchline to a friend as you're walking by the annoying someone.
Repeat this ritual (making sure the annoyance can hear you) constantly, but never tell the annoying someone the rest of the joke.
It will eventually drive them slightly insane!
The punchline is: "And then the president said, "But that's not *my* duck!"
What really is the rest of the joke? In your dreams, baby!