Self-defining memories represent significant emotional events capturing the most important concerns in our lives. While much HCI work on memory technologies has focused on autobiographic memories and lifelogging technologies for capturing them, there has been little exploration of self-defining memories and how they may be supported by appropriate cues. This is important as such memories are key in the development and maintenance of sense of self, particularly in old age. We report on interviews with 8 older adults in their homes. Findings advance the understanding of self-defining memories and their possible cues with new insights into their relationship with self identities and cues’ specific qualities supporting richer emotional recall. Our findings led to several design implications such as novel technologies for curating self-defining memories and their cues, for embedding layered meaning in such cues across the lifespan, and for crafting them.