The question of identity narrative is at the core of the interaction between social movements and temporalities. In this paper, we draw on long-term qualitative research amongst activists engaged in Italian social movements and argue that identity narratives are often the result of a complex mnemonic, contradictory and open-ended process that spans through a life-time of engagement with multiple collectives. We then question whether the use of social media reshape these dynamics. The analysis shows that the construction of identity narratives on social media tends to take place with knowledge of the complexity and overlaps that characterise these processes online. Nevertheless, the temporality of social media, based on immediacy, archival and predictive time, challenges the unpredictable, contradictory, and open-ended nature of political identity construction offline. The need to escape the hegemonic temporalities of social media poses new challenges to activists in their creative agency.