‘Twas quite a day. Seventeen hours, a big sound stage, a crew of 40 or so, reps from Sprint, creatives and producers from two agencies — and a lot of slicing through foam with chainsaws. It was my first big national spot. For years I’ve been knocking at that door, always knowing that I had the chops. But what I didn’t realize is I only recently had the temperament. With so many people so invested, and so many moving pieces on the set, I found my inner Zen.