I have a photograph at home of Fred Astaire from the knees down with his feet crossed. It's kind of inspiring because it reminds me his feet were bleeding at the end of rehearsals. Yet when you watch him, all you see is freedom. It's a reminder of what the job is about in general, not just being in musicals.
On the screen were some flashback shots of Daniel, Emma and Rupert from ten years ago. They were 12. I have also recently returned from New York, and while I was there, I saw Daniel singing and dancing (brilliantly) on Broadway. A lifetime seems to have passed in minutes.
In theater, you've got to be aware of your whole body because it involves stamina. It involves two-and-a-half hours and a sustained release of energy, maybe for six months.