In this essay, I consider a kind of social group that I call ‘epistemic’. It is constituted by its members’ possession of perceptually grounded common knowledge, which endows them with a particular kind of epistemic authority. This authority, I argue, is invoked in the activity of ‘joint reminiscing’—of remembering together a past jointly experienced event. Joint reminiscing, in turn, plays an important role in the constitution of social and personal identity. The notion of an epistemic group, then, is a concept that helps explain an important aspect of a subject’s understanding of who she is.