You know mastery when you see it — on the stage, on the page, or on the field. But beyond raw practice, what actually creates mastery? In this monthly issue, we explore what mastery is, how it’s cultivated, and, perhaps most intriguingly, why some people are willing to trade it all for a chance to be the best. Inside, neuroscientist Rachel Barr speaks with author David Epstein about the systems that build star performers. Philosopher Massimo Pigliucci examines the ancient idea that we can only truly master one thing in life.