Knock knock. Who's there? Bye.

Bye who? Bye-gone conclusion, I'm leaving!

Knock knock. Who's there? Next.

Next who? Next time, just open the door, this isn't a surprise party.

Knock knock. Who's there? Recursion.

Recursion who? Recursion who? Knock knock.

Knock knock. Who's there? Vaughn.

Vaughn who? Vaughn voyage! Hope your journey's ship-shape and full of bon-bons!