In 1953, a twenty-seven-year old factory worker named Henry Molaison, cursed with severe epilepsy, underwent a radical new version of the lobotomy that targeted the most unexplored structures of the brain. The operation was performed by Dr. William Scoville whose brilliance as a surgeon was only tempered by an adventurousness that bordered on recklessness. It did not cure Molaison’s seizures but left him profoundly amnesiac. This tragic, if revelatory, accident opened the door to our understanding of how memory works and Molaison—better known as Patient H.M—was studied for over sixty years, becoming the most important research subject the field of neurology has ever seen. In 2003, Esquire contributor Luke Dittrich—Scoville’s grandson—set out to learn more about this seminal case in his feature, “The Brain that Changed Everything.” He joins host David Brancaccio to discuss the story and how it led to his seven-year journey to write a full-length book, Patient H.M.—published this summer—a fascinating journey about the history of neuroscience, his grandfather’s methods, and buried family secrets.