As you grow you will keep appreciating the growing amounts of personal development
Eventually you think back to when you were worried about turning 25 and you'll think "why would I ever wanna be 25 again? I had so much less knowledge and experience back then"
I was so nervous about turning 30. The thing is that nothing happens when you do, except you're no longer nervous about turning 30. It was honestly kinda freeing to just get it over with.
I'm in my fifties too, but look back on 25 year old me and see a fucking idiot. I know it's true because I'm a lot smarter now, but still a fucking idiot. I wouldn't mind a 25 year old spine, though.
41 here, I was there too. It's not that bad, just take care of yourself now. At your age I ate fast food, never exercised, and basically lived on caffeine, nicotine, and stress endorphins from working all the time. Now at my last check up, I'm overweight, my knees are shot, my back hurts all the time, and I have chronic acid reflux.
You are young enough that you can get a head start on aging, what you should do daily is exercise, eat healthy, and take some personal time/mental health time for yourself everyday to reduce stress. You don't want to end up like me and be facing a huge uphill battle to get healthy.
The optimal age is 28. It's late enough that you may at least be hitting a stride professionally (though don't stress too much if you're not), you've chilled out a bit from your earlier 20's, and your body (generally) hasn't begun to betray you yet.
25-35 is a great time. I moved cities and changed careers in my late 20's, and pivoted again in my early 30's, and it was a good reset to build on lessons learned and undoing past mistakes, while having the youth and energy to really enjoy myself and actually choose a path I was going to have fun with.
I'm enjoying my 40's a lot, but I look back fondly on that 25-35 period as being both fun in itself and setting me up for a good 30's and 40's (and possibly further).
The 'optimal' age is whatever age you are right now, no matter what state you're in, and I'm a miserable old bastard. Otherwise, apart from that one moment, you're always living with either hope or regret.
Ah yes, the old quarter-century crisis. We got another one here, Bob, send em the welcome package. (The welcome package is multi-vitamins and sore knees)