A common theme in accounts of choosing mathematics is that of persistence in the face of troubles or difficulties which are often associated with the structuring effects of gender, class, culture and ethnicity. Centring on an analysis of one woman's account of becoming a mathematician, we build on our understanding of multiple and developing identities with the aim of capturing the nature of individual challenge to structuring discourses and its implications for choice and participation in mathematics more generally. Inspecting how she talks about events in the past, present, and future, we expand on Leont'ev's (1978, 1981) notion of leading activity to explore how we organise and prioritise activities (and their related identities) within the context of Holland et al.'s (1998) theory of identity in practice, hybridity and world-making. We interrogate the part played by contradiction in creating a space for individual agency through its resolution in hybrid practices and its relation to social change, exploring how our informant narrates taking up mathematics "against the odds" as part of an ongoing process of "re-writing" herself into new imagined worlds. In providing an insight into how one individual envisages and enacts a different mathematics culture in which she can have a place, our analysis suggests ways forward in creating new, more inclusive, mathematics education.