In this article we develop the idea of ethnography as a practice of desire lines. Lines of desire are pedestrian footpaths that are at once amateurish and playful, and that deviate from the grids and schemes of urban planners. We argue that ethnography has always been so at the same time as also being highly professionalized. The article explores these tensions between desire lines and professionalization as they became evident to us during a funded, international multi-modal ethnographic study with children—a study, we argue, that rendered us childlike. We conclude that being childlike and ‘out of line’ is an appropriate and necessary response for knowledge creation at a time of heightened professionalization in the academy.