Why?

"Oh! Joanna, please sit down on your bum!" I stated from across the kitchen.
"Why, Mommy?" was the immediate reply.
I was somewhat taken aback since this was not a new direction. "Because the chair is not stable and I don't want you to fall over and get a bonk on your head!"
"Why, Mommy?"
"Because that is what will happen! It's called gravity!" came my oh-so-scientific reply.
"Why, Mommy?"
"Because that's how God created it!" I was quite pleased with myself for thinking that quickly. Not for long.
"Why, Mommy?"
"Oh look, Joanna! You finished your lunch! Good job! Time for nap-nap now!"
Joanna responded with an enthusiastic, "Oh! Nap-nap! Bye-bye Kitchen! Bye-Bye shoes!"

Any mothers out there with better pearls of wisdom for the "whys?" :-)