It's the feeling of working towards a clear goal; making visible progress everyday. Of feeling challenged and stepping up, and knowing that you can take this so so so much further and that you will. The primal sensation of having pushed your body physically.
My appetite is better, too: I'm ravenous in between bouts of movement and dance choreo; need to keep my blood sugar up. I feel clear-headed and bright-eyed.
It's getting on the other side of the desk again.