Why do I always dance?

I had the privilege of substituting at our local elementary school for a week and a half, where I got to do... TA DA! LUNCH ROOM DUTY! It was great fun.
After a few days, one of the students at the lunch table looked up at me with wide eyes and asked, "Why are you always dancing?"
Surprised, I asked, "Am I always dancing?"
"Yes!" several students replied.
I thought fast. There had been some occasions when I was wandering past tables, monitoring students' food intake (or lack thereof) when I'd spun on the balls of my feet, for no particular reason, but it WAS fun to see my skirts twirl out and around. Other times I wore tappy shoes and I couldn't help but tappity-tap them a few times now and then. That must have been the dancing they were referring to.
"Because," I said, "Dancing is good for you. It keeps you healthy and makes you happy. You should try it!"
I caught some incredulous looks, then did a twirl and moved on to the next table.
You know what I didn't tell them? If you do a few dance steps, you can eat your whole school lunch with fewer pounds gained.
And the sweet rolls are worth it.
Oh, yeah!