Much prior groundbreaking research has been done in recent years highlighting the qualities, quantities and means children have to enter transpersonal states of awareness. As important as this precedent research has been, in many ways it has yet to fully appreciate the gravity of childhood transpersonal experiences in terms of the impact on children and their personality development from not integrating their transpersonal experiences. This present study not only looks at the qualities, quantities and means of childhood transpersonal experiences but reveals reasons children have for not integrating such experiences and the resulting impact of not integrating their most meaningful moments. The research derives from dissertation interviews with 12 adults recalling their childhood peak experiences (CPEs). Qualitative thematic content analysis was applied to the interview transcriptions and revealed five main themes with more than 100 supporting sub-themes. The research has discovered a composite experience of CPEs that consists of (a) qualities of the CPE, (b) the reasons for not assimilating CPEs, (c) the experience of sharing CPEs, (d) the unassimilated positive qualities of CPEs, and (e) the intrapersonal and interpersonal impact of non-assimilation. The author terms this distinct composite process CPE non-assimilation and describes how it played out issue by issue in the developmental lives of 12 high-functioning adult professionals.