Anger management

On the way home yesterday, Sarah was telling me about her day at school:

Sarah: I was a very good girl, Mommy. I didn't cry and I didn't hurt anyone and I didn't have to sit out.
Me: That's great! I'm very proud of you!
Sarah: Yeah. And my head makes me mad.
Me: Your head makes you mad? (???)
Sarah: Uh huh. It makes me mad, and my body tells it to.
Me: Umm, your body?
Sarah: Yeah, my head makes me mad because my body tells it to do that. (I expected her to say, DUH, you idiot!)
Me: (totally confused - is she hearing voices??) Well, okay.