This article is one of the first attempts to materialise Joanna Haynes and Karin Murris' conceptualisation of the post-age pedagogy that focuses on loosening the boundaries of age-based expectation. The project is conducted against the backdrop of the discourse of ageism existing hand-in-hand with various age-transgressive practices. It involved multiple case studies of child and adult readers' responses to two picturebooks, i.e., How to Five Forever (1995) and Grandpa Green (2011). The two research questions are: how do children and adults respond to Forever and Grandpa? What is the pattern of similarities and differences in their responses? In addressing these research questions, the present study aims to facilitate the emergence of a post-age picturebook pedagogy. The findings reveal that a post-age picturebook pedagogy should acknowledge the chance of holistic learning opportunities that picturebooks can offer to both children and adults, including, for instance, aesthetic appreciation, literary understanding, emotional engagement, and material experience. Such a pedagogy involves an egalitarian view of child and adult that acknowledges some biologically determined differences subject to the factor of age and meanwhile emphasises their shared humanity and idiosyncrasies, thus undermining the binary division between simple child and sophisticated adult. The material affordances of a picturebook can be deployed to amplify the points of connection and dialogue in child and adult readers' responses and a post-age picturebook pedagogy should strive to enrich interpretive and experiential possibilities for diverse readerships. In comparison with the existing empirical studies using picturebooks, this project positions adults as readers who can enjoy picturebooks for their own sake rather than co-readers whose responsibility is mainly to facilitate child readers' learning and development. It stresses and seeks to maximise the potential of picturebooks for creating a beneficial and pleasant experience for all involved, both child and adult, an aspect that has long been overlooked.