In Daniel Gilbert's book, "Stumbling On Happiness" he demonstrates that humans are horrible at predicting how they will feel about future events. We shoot for an unknown future only to get to that future moment and be unsatisfied with the circumstance.
As we gain experiences through daily life is shapes our context and experience. I could not have predicted how I would feel or where I would be as a 35 year old when I was 20. Sure I thought I knew but I didn't know ... I couldn't know.
Although a part of our core is constant we still change and are shaped by our experiences. It should be that way. You should be growing and evolving as a person.
This thought really came to a head today as a was reading a book I first read 15 years ago. I still had my original highlights and notes inside this book. But what stood out to me was the parts I didn't highlight the first time through. Things that I had no context or experience to understand when I was 20 all of a sudden had profound impact and importance.
I think re-reading books that have had impact on you is a good way to see this principle in action. You will gain new insights because you have a whole new set of experiences with which to view the material through.
So just 2 points to end this:
1. You should be growing each day. Gain new experiences and wisdom from each interaction you have with another human being. Everything interaction can teach us something if we are open to it.
2. We are horrible at predicting how our future selves will fill or be. So instead of time traveling to the future embrace today and everything in it. If you fully live this day you will look back on a life well lived. Don't miss out on the blessings in front of you to try to chase down some elusive state in the future.