An animation based on a theory of Julian Baggini, who studies the complexities of personal identity, offers a counterintuitive answer to the question. There are lots of different processes in the brain, all of which operate, in a way, quite independently. But its because of the way that they relate that we get this sense of self. He calls it the ego trick. Its not that we dont exist, its just that the trick is to make us feel that inside of us is something more unified than is really there.