I'm not sure it's ever too late to learn anything. Unless you are dead.
But I do wish I'd been able to feel ok about my body as a teenager, the anorexia was harmful to my bones & heart, so I guess technically I learned too late to value my body, or learned it too late to avoid damage anyway, though I'm pretty healthy overall now. I think almost all teenagers are uncomfortable with their looks in some way, at least they were back then.
I have elderly family that seem miserable because they never bother to learn or achieve anything since they are "too old" for it to matter.
They assume retirement is just lounging around all day until you die. They don't pursue hobbies, read books and are not very active since it "doesn't matter" .
I read somewhere that if you actually wanted to feel good when you were old, it took 3 hours of exercise every day (meaning physical activity, not 3 hours of weightlifting). Which made sense to me, and I figure if I'm able, that's what I'll do if ever lucky enough to retire. I don't have a spare 3 hours a day now but have increased my daily movement to get ready so it's not a shock, lol. So they could be depressed because of physical idleness.
But it seems hard to never learn anything, unless you are making a very intentional effort not to!
My grandpa likes to talk about how it’s when people stop doing things that they begin the downward spiral. He’s not doing the best at the moment himself but by the standards of a 90 year old he’s doing amazing.
Accomplishment and knowledge are their own rewards, aim for a high score in them