The notion of memory plays a central role in the discourse on the preservation of cultural heritage. However, the term is often used in an ambiguous way. This article refers to research work on individual and collective memory that can contribute to a clearer definition of the concept and open up new perspectives for conservation theory. It focuses on impermanent artworks that are available in a physical way only when they are performed or installed, and argues that they are particularly at risk of being forgotten. In fact, memory items do not automatically persist in the longterm memory of a group but need to undergo a consolidation process. If impermanent artworks are not archived, made accessible to the attention of the public and recalled regularly, their memory cannot be consolidated. At the same time, as this paper points out, retrieval is not an objective act but a reconstruction process that can modify memories. In this context, some key concepts of conservation such as reversibility, reconstruction, consolidation and artwork identity are considered from the perspective of memory.