There are strong parallels between recovered memories and multiple personality disorder, both are associated with child sexual abuse and both involve dense amnesia of one kind of another. Recovered memory is inherently unstable. Since it is relatively stable, the properties of multiple personality disorder have been investigated experimentally in one or two cases. This enables psychology modelling to be carried out with more confidence. The Headed Records Model (Morton, Hammersley and Bekerian, 1985) is used to develop a concept of self which provides leverage in understanding, M.P.D. Recovered memories can be understood in a similar way. False memories are only slightly, though significantly different. There is no bar to this coexistence.