For people with Highly Superior Autobiographical Memory, or HSAM, every day is memorable. Ask them what they were doing on this date 10 years ago, and they’ll be able to tell you. Markie Pasternak, one of the youngest people identified with HSAM, and Michael Yassa, PhD, director of the Center for the Neurobiology of Learning and Memory at the University of California Irvine, talk about what it’s like to have this ability, what we know about how the brains of people with HSAM store and retrieve this vast amount of autobiographical information, and what studying this unique ability can teach us more generally about how memory works.