Punchlines

Isaak to Anya: Knock-knock, who's there?

Anya: Who's there?

Isaak: Mr. Nobody! Don't cry, it's only a joke! (Insert contagious 2-year-old giggles here)

Because once upon a time, he heard his sisters say:

Knock-knock

Who's there?

Boo!

Boo, who?

Don't cry, it's only a joke!