do most artists produce their best work in their early 20s?

It's a myth, just like the scientist one.

The fact is that people in their 20's usually have the energy to push their ideas and don't know when to stop. They also have a lot fewer ideas.

We "ancients" often have more ideas, but just can't be bothered making them available to today's copycats.

I don't know if that's true. But if so, then I would say it's  because people are full of vigor. Maybe you just run out of creativity, like women run out of egg cells, as they age.

As athletes need a healthy body, artist and scientist need a brain with all neurons firing. 

No, I don’t think so.  Many artists change and develop.

It might be statistically true but there are plenty of exceptions.  There's no real reason why people can't create art at any age.  But it is true that a lot of artists do their best work relatively young.  Personally I can't figure it out because they can't have had enough life experience yet but what do I know?

I would say that most artists and scientist produce their best work well after their early 20s..... unless you count fleeting pop-music acts as "artists".... Most great scientists, meanwhile, are still in school well past their early 20s...

Grandma Moses STARTED at age 80.

My name isn’t colly stop it