It's confusing to watch myself age.
On the one hand, at a fundamental level I do like and do the same things: reading, writing, sleeping, low stress, intellectual challenges, curiosity, walking and cycling, swimming, but not team sports. Like animals, want a dog, avoid crowds, dislike heat, like hugs in mild doses, want to learn how to fly an airplane. Feel socially inept but probably am doing average. Just to name a few random things.
On the other hand I changed quite a bit: I toughened up, took on consulting and some positive social traits ("the way of the weasel", I sometimes call it), can't relate to some of my hardcore engineer friends anymore, drifted culturally to the Dutch blunt style. Lost some of my magical thinking, expanded my interests to economics - I read annual reports for fun now, instead of technical IETF standards. I also enjoy the company more and more of younger people around me (5 to 25 years old), where I used to sit with adults (35+) and elders.
I used to enjoy concepts more than the practical implementation. Now I think concepts by themselves can be a good start, but are sort of useless if there's no practical angle. Ideas are cheap.
My guess is the fundamentals will stay, and I actually worry right now I'm not growing enough as a person anymore (who decides what's enough?). I want to be financially free, and for varying definitions of 'free', I am. Just to feel 'free', and unconstrained. Being confined in a daily grind or even obligations feels like prison. It's a given at this point.
The implementation details probably will vary, and I might try a nutty thing or two that I know are not good for me. Or force myself in a comfy prison because I know stability and structure are actually great for my baseline happiness.
On the third hand: I'm not even sure who I actually was when I was younger. That person is gone anyway and impossible to retrieve. Sure, I have some memories, but they are unreliable, patchy. Some recurring images I know I made up are getting very close to feeling like real memories. Who knows that hasn't happened yet? I sure couldn't tell.
I have a few friends that have known me a long time, and family, but they don't really know the full me now do they? We all have our images, storylines, preconceptions and perceptions, make a story out of it and that was 'me'.
Or to put it in Arnold terms: "You are not you, you're me"
Go figure.