While complexity thinking features increasingly in the education and physical education literature, there remains a paucity of research presenting evidence of the influence that complexity principles have on learning. We further advocate that more work with complexity thinking is required to investigate how teacher educators engage with key complexity principles in their work with students and teachers. Accordingly, in this paper we investigate how one group of teacher educators, the Developmental Physical Education Group (DPEG), have grappled to develop their own knowledge of complexity thinking while concurrently attempting to support students and teachers in their efforts to apply these principles within local schools. Employing methodology from self-study, the paper provides data from two focus group interviews carried out in 2012 and 2014 in which six members of the DPEG discuss how they wrestled to understand, share and support the application of complexity thinking in practical contexts. In particular, the paper explores how the group members worked with complexity principles such as self-organisation, emergence and 'the edge of chaos' to develop innovative pedagogical strategies with children, students and teachers. Findings from the study reveal how all members of the DPEG, in their initial engagement with complexity principles, raised questions about their personal approaches to the teaching and learning process but also struggled to use the principles to inform their practice. Two years later, however, as the group's confidence with complexity thinking grew, the members had created a shared understanding and language around complexity thinking, were more comfortable debating issues around complexity and also describing how key principles had impacted upon their pedagogical strategies in practical settings.