My daughter has entered the why phase of childhood. I really didn't expect it to start so soon. She's not even three yet! Several times today she asked a question and when we answered it the next thing out of her mouth was...but why.
Curiosity! Asking why is how they learn, keep on giving her answers. You don't want her to stop asking and stop learning. Kids learn a lot when they are between 2 and 5.
I think that is cute. I know sometimes it is annoying, especially when the answer is obvious or when you don't really know the answer. Still, that's cute.
Our youngest likes to trick people with the "why is this..." and "how come that" game. Of course we try to warn others but she is pretty quick to use her charms to sucker them in.