When DD hammered me with a question barrage, it was, "What's that?" There's nothing like a hardware store for overstimulating a curious 2yo. I couldn't even begin to formulate one answer before she'd moved on to something else.

When she was 3, her questions weren't disproportionately "why" questions; a lot of them were information seeking. "What happens to food when you eat it?" "Tell me some more about jail." "What are these pictures showing?"

"Why" could always be expected to show up when DD was being told to do something she didn't want to (or told not to do something she did want to). "Why do I have to wear pants outside the house?" "Why do I have to hold your hand in the parking lot?" "Why can't I have more candy?"