generally speaking success is a result of favorable conditions that allowed one the opportunity to work really hard at a skill for no pay and become very, very good at it
it's a different kind of hard work, because generally it's a delayed reward.
i think most people work hard. rich people were able to use their labor as a long term investment, rather than an immediate transaction. that may have been due to having a background that was already well-to-do, or simply because the skill they were developing was not yet well-known and it was easy for them to spend a lot of time on it.
generally compensation differences happen because of replaceability, not because of 'how hard you worked'. so for once the evil pointy haired boss was right: work smarter, not harder
And when the hourglass has run out, eternity asks you about only one thing: whether you have lived in despair or not.