Somewhere around mile 48 of the Susan G. Komen 60-mile walk in Boston, my body started loudly protesting and I learned a massive lesson about how negative self-talk and self-sabotage dictate our physical limits. For the first two days, every time I passed a cheering station or volunteer crossing guard decked out in pink and huge smiles, I was met with a simple question: "How are you doing?" My enthusiastic response? "Fantastic!" or "Wonderful!" And every single time I said i