This chapter deals with "collective" memories, the factors that affect them, and the psychological/social functions they accomplish. It discusses the classic construct of "collective memory" first proposed by Halbwachs at the beginning of the 20th century. The chapter explains how this apparent paradox of a memory of an abstract entity which does not exist independently from the individuals is possible. Flashbulb memories (FBMs) are the paradoxical example of the subjective linking between external, public events, and the personal experience of the individual. FBM is considered as a kind of emotional memory, thus the same cognitive processes activated by ordinary emotional experiences are involved in its formation and maintenance. Generational memories, reminiscence bump, and FBMs show that the memory for public events links very strictly the memories of individuals to a collective dimension.