On the eve of my latest marathon training cycle, I’ve been thinking a lot about quitting. More specifically, I am interested in how we talk about it: “Quitters never win.” “Try, try again.” “#noexcuses.” It’s always presented in this clear dichotomy – quitting is bad, no matter what. Finish at all costs. Michael Jordan said, “If you quit once it becomes a habit. Never quit.” And few can forget, try as we might, the words of the immortal Chumbawumba: “I…