Research on social memory phenomena is confronted with the problem that social memory has neither a substrate in the sense of a remembering subject nor a central organ of an operating memory in the sense of a human brain. As a consequence, social memory exclusively exists between subjects and not within them, its form of existence consists of communication. In its first part, the article presents examples of family conversations that show that family memory does not serve as storage for memories, but rather serves as a catalyst for the most different elements of the past to be specifically combined by the involved persons. On the basis of a replication of Bartlett’s classical experiment on remembering and re-narrating, the second part of the article demonstrates that the acquisition and transmission of imaginations of the past follows patterns that are specific to the respective generation. This leads to theoretical remarks on the constitutive viscosity of social memory.