"Why?"

We always knew it would come to this. We would one day be faced with the question of "why" in response to just about anything and everything we presented our darling three-year-old.
And so it has hit.

Example:
(me) "Please go and brush your teeth."
(Big-A) "Why?"
(me) "Because we are going to go to school soon, and we need to get ready."
(Big-A) "Why?"
(me) "We brush our teeth before we go out."
(Big-A) "Why?"
(me) "To prevent cavities and keep our teeth healthy."
(Big-A) "Why?"
(me) "Please just go and brush your teeth."
(Big-A) "How?"
(me) "Go upstairs, get on your stool, put toothpaste on your toothbrush, and brush your teeth please."
(Big-A) "Why?"
(me) "Because I said so."

I do have to credit him with occasionally interspersing the "why's" with the occasional "how".

Can I have a glass of wine yet?