Repeaters of that quote invariably neglect to mention that those are the words of a fictional character that lived to be at least two thousand years old.
Several are currently running for President.
I find it very relevant that a person who does all these things is a (fictional) character that lives for thousands of years; that means he has plenty of time to learn a lot about many different fields and trades. Normal humans don't have this luxury.
Methinks you've missed the point.
You can argue that the sentiment expressed by the fictional character is impractical, as you do in the last part of your comment. I disagree with you, but that's neither here nor there.