Thats YOUR life, Mama!

I picked Thing 3 up from school today, and she was telling me that when she grew up, she wanted to be a pet doctor. I asked her what a pet doctor did (thinking that she thought all she would have to do is play with the dogs) and she told me: "Well. I'll give them their shots, fix their broken legs and take their tumors off."
She hit it pretty right on.
Then she asked me: "Mama. What do you want to be when you're all growed up?" I told her that I was already grown up. She said: "No Mama. What do you want your job to be when your growed up?" I again told her that I was all grown up, and that I was her Mommy.
She sighed rather loudly, "No Mama! That's just your life. What do you want to BE, like your job?" I thought about it, and said "Well. I want to be your Mommy." She was getting irritated with me, "No Mama! THAT IS YOUR LIFE! What do you want to be your job? Like work in a store, or be a pet doctor like me, or a tooth doctor...what?"
That's just my life... to be a Mom?!?
I really had nothing to tell her, because really, I don't want to DO anything else.
I said: "I guess I could be a teacher or something."
She smiled, and said: "Thats good Mama. You teach good."