Why a Duck?

I am back from a quiet week on the slopes.

Prodnose: Alright, why a duck?

Myself: (pause) I'm not playing "Ask Me Another," I say that's a viaduct.

Prodnose: Alright! Why a duck? Why that...why a duck? Why a no chicken?

Myself: Well, I don't know why a no chicken; I'm a stranger here myself. All I know is that it's a viaduct. You try to cross over there a chicken and you'll find out why a duck.

Prodnose: When I go someplace I just...

Myself: (interrupts) It's...It's deep water, that's why a duck. It's deep water.