Abstract The alleged and disputed repression of serious, traumatic and repeated childhood sexual abuse memories, and their recovery, usually with psychotherapy and ‘memory recovery techniques’, have become a major social phenomenon in the last 15 years. This review picks out the key historical, theoretical, research and legal milestones during that period. Key concepts and a review of the inconsistent usage of language and definitions are highlighted to assist the reader to understand the nature of the dispute. A comparison is drawn between this phenomenon and the parallel social history of claims of alien abductions in the US for the purpose of hybrid breeding. A comparison is also made between the boundaries of natural memory functioning as currently understood, and that imputed to questionable recovered memories of childhood sexual assault.