"It was a summer day in 1941. The circus had just arrived in the tiny town of Brookfield, New York. Spectators flocked to see the wire-walkers, the tramp clowns -- if they were lucky, the human cannonball. They also came to see the strongman, Johnny "Bull" Walker, a brawny bully who'd pin you for a dollar. ...Now, the strongman hadn't told anyone, but he was actually a third-year medical student. He toured with the circus during summers to pay tuition ...over the next five decades, he'd draw on these dueling identities to forge a whole new way to think about pain. It would change modern medicine; so much so, that decades later, Time magazine would call him pain relief's founding father."