Our brains are far stranger than we think. We remember, feel emotion, navigate, empathize, and understand the world around us, but how would our lives change if these abilities were dramatically enhanced—or disappeared overnight? British science writer Helen Thomson has spent years tracking down extraordinary brain disorders, and presents nine unforgettable people here—among them a man who thinks he's a tiger, a doctor who feels the pain of others just by looking at them, and a woman who hears music that isn't there. Beyond exploring the clues such cases give us into the workings of the mind, Thompson explains how to forge memories that never disappear, make better decisions, and make yourself happier in a split second.