Morgan and Hansen suggest that further research is needed to explore how non-specialist primary teachers approach and teach physical education (PE) based on their personal school PE backgrounds, teacher education experiences and ongoing professional development. This paper adopts Lawson's socialisation model, a theoretical framework subsequently used by many other researchers, to explore how primary teachers' experiences in various contexts "shape [their] knowledge and beliefs about the purpose of physical education, its content and teaching approaches". Examining teachers' beliefs and attitudes towards PE is arguably important as it highlights how they approach the profession and enact particular teaching practices. We examine the views of 327 non-specialist primary teachers who participated in a postgraduate certificate in primary PE run by the Universities of Glasgow and Edinburgh. This article reports findings from the baseline data of our longitudinal research--arguably crucial in ascertaining teachers' starting point and useful in monitoring the programme's impact. Our findings suggest the prevalence of negative PE experience during primary and secondary years, which we considered part of Lawson's "acculturation" phase. Experiences during initial teacher education (ITE) or "professional socialisation" showed that teachers were only given a basic starting point, which was inadequate for teaching PE effectively. The initial teaching experience or "organisational socialisation" stage also presented major challenges for teachers who endeavoured to apply knowledge and skills acquired during "professional socialisation". We suggest that how teachers' conceptions about PE are formulated and the accounts of challenges they encountered upon school entry are vital for the design and delivery of effective ITE and PE-CPD. Additionally, these findings underpin the need for more critical and reflective learning experiences at all levels of PE.