Following the work of Jacques Derrida and modern educational authors, this article argues that Western education currently holds mainstream formal educational practices as the standard by which all other educational practices should be judged. This is a problem because this positions every other educational practice, including non-formal education as supplemental to formal education. Derrida calls this the logic of supplementarity. Drawing on data from over 2 years of research in Flemish youth work, that the logic of supplementarity inhibits non-formal educational environments in articulating their own educational goals. We conclude that supplementarity is an unavoidable characteristic of education, and that exactly by acknowledging practices as supplemental, it becomes possible to work towards a Derridean ideal of an education 'yet-to-come.' In this logic, we argue, it becomes possible for non-formal educational practices to both challenge formal conventions and to better their own practices.