Stupid

While I was taking a walk this morning I overheard this conversation between two people discussing a garden fixture:

Person A: "What is that?"
Person B: "It's a fountain."
Person A: "Oh, it's a fountain. So is it for water?"

Person B's response was much kinder than mine: "yes."

My response would have been: "No, it's one of those new air fountains. It uses air. Want a refill?"