After reading so many negative reviews of this movie, I wondered why I liked it so much. One reason of course is that I'm philosopher and I really love the topic of personal identity in philosophy of mind. But this coudn't be true. This could not be the main reason for my positive evaluation of this movie, for certainly the story is rather naive and the critics are right about so many holes in the story, and they are right that the actors weren't good in their interpretation. In fact I liked because the movie has a happy end, since I cheered for the idea that persons could survive the diachronic discontinuity of their bodies. And this is just what happened with William's wife and their three kids. We, people, love the idea that we can survive our own bodily extinction. Religion also exists for this very ideia. The movie's plot is a materislist Sci-Fi interpretation of this same core belief about the idea we have about ourselves as persons, and not mere animals.