Valuable memories are increasingly captured and stored as digital artifacts. However, as people amass these digital mementos, their collections are rarely curated, due to the volume of content, the effort involved, and a general lack of motivation, which can result in important artifacts being obscured and forgotten in an accumulation of content over time. Our study aims to better understand the challenges and goals of people dealing with large collections, and to provide insight into how people select and pay attention to large collections of digital mementos. We conducted an interpretivist analysis of forum data from UnclutterNow.com, where participants discussed issues they face in curating the sentimental artifacts in their homes. We uncovered a number of social, temporal, and spatial affordances and concerns that influence the ways that people curate their memories, and discuss how curation is closely tied to how people use storage and display in their home. In our study, we drew out and unpack "curation regimes" as patterns that people enact to focus the attention they are able to pay to the artifacts in their collections. We close with a discussion of the design opportunities for memory artifacts, which support and facilitate the curatorial processes of users managing digital mementos in everyday life.