This article is actually a good attempt to answer the title question (or rather, show how the question is the wrong one to ask).

...so if the work itself doesn't drive you, you will burn out or fall by the wayside or your extreme competitors will crush you and make you cry...

TL;DR for all who need to ask the question: Don't try this at home. “Being great” is not something you decide and then attain by planned steps.