I use to ask my mother, which of 'ourselves' would end up in heaven. Was it as we were when we were young, or was it as we were when we were wisest?
Years later I heard the story of the irish railway worker in USA who, when his brain was punctured by a large piece of metal (as the result of an explosion) suffered no ill effect other than a complete personality change. Seems he was a thoughtful honest man beforehand (typically Irish, no doubt) but became devious and slothful afterwards. Now which was the real 'self'?
Looks like this books explores those dilemnas