Previous research has shown that people often separate the present self from past selves. Applying knowledge gained from intergroup research to the interpersonal domain, we argue that the degree to which people identify with their past self (self-identification) influences their reaction when recalling a past event during which they harmed another person. Because they feel close to their past self, we expected this to be threatening for high self-identifiers, and expected them to be motivated to avoid self-critical emotions and blame. Using four meta-analyses, conducted on a set of seven experimental studies, we investigated four ways in which high self-identifiers can distance themselves from the event: by feeling compassion, by taking a third-person rather than first-person perspective, by emphasizing ways in which their present self is different to their past self, and by disidentifying with the past self altogether. We found the strongest interaction effects for compassion: whereas a compassion manipulation increased self-critical emotions and self-blame about the past event for low self-identifiers, it decreased them for high self-identifiers. We argue that this occurs because the other-focused nature of compassion allows high self-identifiers subtly to shift the focus away from their harmful behavior. Our concept of past self-identification had stronger effects than a measure of self-continuity beliefs. It also correlated only moderately with the latter, suggesting they are distinct concepts. Our findings suggest that, ironically, the most effective way to protect the self against reminders of an undesirable past, may be to have compassion for our victims.