Depends on the dream, isn't it? I mean if you want to be an NBA player you are not going to become one when you are 65 years old.
These people ended up building business', write, paint and so forth which never required young age to begin with, in fact being older meant wiser and have more time in your hands thanks to being retired and allow them to get more free time to practice and be better. My mother started painting after 60 as well, and suddenly she can paint, she didn't know how to draw stick guy, and now she paints views, all thanks to having free time and being much wiser to understand when studying how to be better at doing something.
I completely agree with what you say, and, moreover, we cannot take these examples as the norm. For me the moral is not to put barriers on yourself as you get older regarding your goals or what you can do, but always being realistic and aware of your goals.
whatever it is, what moves people to achieve their dreams is themselves. the number of elderly people who stop dreaming when they are old is usually caused by many factors and on average it is a health problem. Dreams are one's driving wheel to become a better person from day to day, it's really regrettable if someone stops dreaming just because of old age and declining health.
Well, there are times when circumstances push you to it. If you are 100 years old, you live in a bed, multimedicated, all the close people of your close age such as childhood friends and relatives have died, your children and some grandchildren have also died and you live full of pain despite mediation, the normal is that you do not have many illusions and you are thinking more about eternal rest.