Thanks a lot! As for being old, i'm 50-50 on that. Osu is just mostly muscle memory and hand-to-eye coordination. Sure it can reduce with age, but I wouldn't say that it makes it impossible to improve at osu! I sucked HARD when I started it. But after two years of playing it, I can now do 5* on mouse, i'm sure you can play osu too! The stuff you see on youtube are vastly exaggerated in that, the demonstrated skill is very high, yes, but they do not show you the hours put into it, the hundreds if not thousands of retries to complete the entire song without misses (and i still miss a LOT), i mean you name it!
And it's fine if neither you or I probably cannot do the 6* maps or beyond (at least for now), the good thing with osu is that it has infinite skill ceiling. Maybe I could do 6* after more years, who knows. It sounds like a time investment just for clicking circles on a screen, but that's because we consider 6* as a goal, instead of the process as the goal (big difference). I never expected to do 5*, only 2 or 3 stars and that was it, I just wanted to play the game without thinking of going anywhere. But naturally since it's mainly muscle memory and hand-to-eye coordination, even a half-dying mutant monster afflicted with the black plague technically can improve as long as he has these two biological skills (and most people have it). What once felt impossible progressively becomes your warm-up!
Osu is probably the strongest metaphor of getting skilled at literally anything. You're downright bad when you start, then months after you do a song you couldn't. Then a month later, you gain 15-20% accuracy more on that map, high score, and then a year later, you go 2* above. It's kind of astounding when you then look at all that you did, and see the improvement.
But if still you don't want to get started with osu, that's perfectly fine, we all have different things we enjoy, and you alone decide what success is, not others. Does it change anything in my life that I can click circles faster than others? Nah. But it's a cool hobby from time to time, in my opinion.