Yesterday, my orthopedic surgeon sold me on something I swore I’d never buy: two new shoulders. And he did it with nothing more than pure, unfiltered enthusiasm.

Years ago, when I was trained as a sales trainer, I learned that 85% of any sale comes down to enthusiasm. The same words spoken in a monotone simply won’t get the same results. Yesterday, in that exam room, I got a masterclass in just how true that is.

Several years ago, I began having severe pain in both shoulders. An MRI revealed that my rotator cuffs were irreparably torn. My doctor suggested injections to help manage the pain. The first two rounds, spaced 90 days apart, worked well. But when I went for the third injection, nothing. No relief at all.