General observations: Things seldom work out 40 years later like you thought they would when you imagined them as a '20-something'. Times change, new technologies emerge, old technologies disappear, some things that were very important to you in your 20's or 30's will hold no interest for you at all when you're in your 60's. Your tastes will evolve, as will your ideology. While the really big things such as your faith or love of family might remain constant, little else will. Even the 'life goals' you set for yourself and meet will likely prove to be of little long-term consequence.
The trick, of course, is to accentuate the positives and minimize the negatives. That's much easier said than done.
S