Awhile ago I wrote an essay about this. I read all the thought experiments about the continuity of personal identity - the brain upload, the clone, the swampman, memory continuity, etc. - and came to the conclusion that the only answer is that there is no continuous "me", only future people who have minds very similar to me. Tomorrow I am a different person. Dramatic events like lobotomies only serve to make future persons more dissimilar to previous ones.