Collective memories are memories shared by a group that influence their social identity. The goal of this paper is to focus on two major limitations in current studies on collective memory and show how the hourglass metaphor can overcome those limitations. The first limitation concerns the partial nature of studies devoted to the analysis of collective memory. Studies tend to focus either on the choice of the past (how memory agents mobilise the past) or the weight of the past (how the past affects the individual or the group). The second limitation relates to the temporal dimension of research conducted so far. Most studies only assess memory over a single generation, yet it can have long-term effects. In this paper, we suggest considering memory work as an hourglass, with the collective and the individual at opposite ends and the sand of memories passing from one to the other, filtered through family values and representations. The hourglass metaphor thus provides a helpful tool to explain the formation of collective memories over time and the interactions between the macro, meso, and micro levels. We approach the study of collective memory from an interdisciplinary perspective, mainly involving psychology, political science, and history. We conclude by suggesting three challenges that future studies of memory will need to address: (1) the need to combine multiple approaches; (2) the need to consider the role of generations; and (3) the need to bridge discussion across disciplines.