The OP is focused on the psychological aspect, but I'm also fascinated by how much physiology plays a part in this. If it's true that your body is mostly composed of cells just a decade old (<a href="http://www.nytimes.com/2005/08/02/science/02cell.html?pagewanted=all" rel="nofollow">http://www.nytimes.com/2005/08/02/science/02cell.html?pagewa...</a>), then your body is <i>substantively</i> different than it was the previous decade. And yet, your mental state and memories, at least as you perceive it, seem to be continuous.<p>But back to psychology and society: I wonder how much of this will change in the age of Google and Wikipedia, when you can look up within seconds and find with good certainty of how things were 10 years ago. And, with the persistence of online data, your past may continually impact your life, day to day, in a way that was never possible before in history. I suspect the responses by participants in this study today may vary quite a bit from similar participants 20 years from now.