Background <p>School physical education (PE) is one of the few contexts in which nearly all individuals encounter structured movement. We explored whether adults’ PE memories relate to sport and exercise participation across behavioral dimensions such as engagement, time investment, and participation style.</p> Methods <p>Using a quota-representative sample of adults living in Germany (<i>N</i> = 2,201), we examined whether the affective valence of adults’ memories of PE (PEMV) and the timing of self-reported formative sport and exercise experiences (FSEE) were associated with adult sport and exercise behavior. Analyses distinguished between three behavioral layers: whether individuals participated in sport and exercise, how much time active adults spent on sport and exercise, and how participation was organized across the week. A hurdle model was used for engagement versus non-engagement, and linear mixed models were estimated for engagement volume and participation style among active adults.</p> Results <p>PEMV was most strongly associated with whether adults reported participating in sport and exercise, indicating a gatekeeping pattern. Most respondents remembered their formative experiences occurring in childhood or adolescence, and within these groups, more positive PE memories were associated with lower odds of non-engagement. The smaller group of respondents identifying adulthood as their formative period showed a decoupling of PE memories and sport and exercise participation. Among active adults, associations between PEMV and engagement volume depended on FSEE. Participation style was unrelated to PEMV and FSEE, but varied systematically with age, with younger adults tending toward fewer longer sessions and older adults toward more frequent shorter sessions.</p> Conclusions <p>Our findings suggest that school PE may function as a population-level motivational gatekeeper for later sport and exercise participation. At the same time, the apparent decoupling of PEMV and participation in adults identifying adulthood as their formative period suggests that negative PE memories need not remain associated with lifelong disengagement. Later opportunities to choose forms of movement that better match individual preferences may provide second entry points into engagement. Differences in how sport and exercise are organized across adulthood suggest that promotion efforts may benefit from recognizing that sustained participation can take different forms in everyday life.</p>