Lots of comments here about how to be a successful CEO. We should all be looking at Elon Musk as the prime example. Work 120 hour work weeks when the going is tough, 100 hour weeks when the going's good, and if you're just starting out, spend every waking hour on your product/company.

If you do this, people will tell you you're insane, and you'll eventually stop. That's why Elon is different, because he cannot stop. I feel that this alone explains 90% of the CEO question - who can choose to stop and who cannot choose to stop.