I'm trying to recall a story that must be sixty or seventy years old. I probably read it in an anthology. It felt old even when I read it.
Here's what I remember: A baby was raised completely isolated from contact with the outside environment and other people, rather like the real-world story of the boy in a bubble. But either his father or perhaps a group of scientists decided to do this because they believed this would create a perfect human. And it worked.
The boy grew up to be the brightest person on Earth. People came to him with every problem that couldn't be solved. He was completely healthy and didn't seem to grow old.
And that's as much as I can recall. I know something bad happened, but what it was, I have no idea.
Edit: I think this story is from the 1920s and no later.