This commentary on the developmental dynamics special issue in Human Development identifies a set of common principles shared in the target articles. These common principles highlight how the dynamic approach has matured in the last 20 years into a mainstream developmental perspective. The commentary then discusses three core challenges facing the dynamic approach – the challenge of clear communication, the challenge of clearly defining learning in development, and the challenge of embracing the dynamics of neural systems. The commentary concludes with a charge inspired by Esther Thelen’s work – to be relevant in the lives of children.