I recall a Nova or something on PBS several years ago where an MIT student had built a contraption that did essentially that. The thing that struck him when analyzing the data was how much every day was more or less exactly like the other.<p>He wasn't particularly philosophical about this fact, but I remember thinking this could be very depressing to some people - and jostle others into doing more with their lives.
Still, as the narrator of the linked video says, "trying to make the best documentary of my life" seems to take an odd third-person perspective of one's own existence.<p>In another vein entirely, I've always felt there was something bordering on the "sacred" about memories. They're as personal a thing as you can have. Being able to rewind and see everything that ever happened to me would take something away from that for me. As with many technologies, you'd gain something, but lose something precious too.