We all have a memory of our past. I’m sure you can summon up, after a little thought, a host of recollections on the order of “On this year/month/birthday here I was, and this is what I was doing.”
Of course the person we see in our memories is not exactly who we are now, but rather a somewhat related entity. If I were to meet my younger self from years ago, I suspect I might be startled by how much my earlier incarnation and I disagree about various things, as well as ways in which our tastes differ.
At some point it will be possible, through advanced computer technology, to create an ongoing in-depth map of the current state of one’s personality. As such techniques mature, it will be possible to measure and to chart the personality drift of a given person over the different times of their life.
I suspect that some people will turn out to have changed radically over time, whereas other will be seen to exhibit a remarkable lack of change through the years.
For the life of me, I can’t figure out which would be better.