He gets it from me.

Leif: "Mommy I am going to tell you a joke ok?"

NM: "Ok Leif."

Leif: "What did the car on top of the house say?"

NM: "I don't know Leif what did the car on top of the house say?"

Leif: (Silence.)

NM: "What did the car say honey?"

Leif: "That was the joke mommy. The car on top of the house is funny!"