Shared stories are the glue of our social lives. We spend a majority of their lives sharing and remembering experiences with others. Couples, friends, families, study groups, work teams, and more broadly, members within communities and societies develop shared memories of the past to fulfill a variety of personal, cultural, educational, and political goals. These collective memories have long been topics of interest in the domains of history, anthropology, sociology, and social psychology. However, over a century of cognitive-experimental research on memory has almost exclusively focused on individuals working in isolation. Using principles developed over 100 years of experimental research on individual memory ability, we investigate social influences on memory. This paradigm shift opens up the opportunity to examine how remembering by a group reshapes the memory of each member and of the group as a whole, and how the flow of such information in social settings can provide insights into issues related to education and public health. I will discuss data and theory from my lab on the cognitive mechanisms that shape how people remember - or forget - the same information, and how the structure of the social network people inhabit can change memory propagation. Together, these experimental tools help unveil how collective memories emerge.