Adults are the ones who do the social science that takes young people as its object. In this paper, we draw on empirical research, social theory, our background in Youth Studies and, for one of us, experiential knowledge as a ‘former’ teenage parent to trouble the practice of social science, in general, and Youth Studies, in particular. Using teenage pregnancy and parenting as a lens, the paper explores what it might mean to work at/on the limits of reflexive hindsight. We suggest that reflexive hindsight offers a particular, limited intervention into the knowledge practices of social science; one that makes explicit and plays with the ambivalence and ambiguity, even irony, of adult social scientists – who once were young – taking the behaviours and dispositions, the hopes, the fears and aspirations, the past, present and futures of young people as their objects