Female underrepresentation in postcompulsory physics is an ongoing issue for science education research, policy, and practice. In this article, we apply Bourdieusian and Butlerian conceptual lenses to qualitative and quantitative data collected as part of a wider longitudinal study of students’ science and career aspirations age 10–16. Drawing on survey data from more than 13,000 year 11 (age 15/16) students and interviews with 70 students (who had been tracked from age 10 to 16), we focus in particular on seven girls who aspired to continue with physics post-16, discussing how the cultural arbitrary of physics requires these girls to be highly "exceptional," undertaking considerable identity work and deployment of capital in order to "possibilize" a physics identity—an endeavor in which some girls are better positioned to be successful than others.