This article explores teacher learning and development, drawing on insights gained during two study visits and an international collaborative project. The article also charts a phase in the author's own learning, reflecting a growing recognition of the complexities of professional growth, gained through listening to teachers. A tentative process model for teacher learning and development is constructed from related literature, which is used to analyse teacher accounts heard during study visits. While critical aspects of professional growth can be discerned in this model, interactions between purpose, opportunity and response are inadequately framed, leading to further interpretations through complexity thinking. In particular, teacher agentive responses appear to interact recursively with development purposes and opportunities, with implications for further research and development in this field. It is suggested that more useful insights are likely to emerge through studying the detail and nuances of interactions and intra-actions in specific contexts, rather than seeking average effects across samples.