Sure. You're right. Unless you also want to have a social life, or fulfilling relationships with people. I won't say that it can't be done, or that it can't be done to some degree, but it's much harder to sustain other parts of your life if you're spending so much time on one thing.

If you're spending 16 hours a day painting, then you might change the world of art. If you're spending 16 hours a day working on your business, you might change the world of business. Or at least your business. But you sure as hell aren't going to have a happy spouse. You're going to lose connections to friends.

This is especially relevant at this time of year. As any Christmas movie will tell you, thinking only of yourself and your work is not going to make you fulfilled.