Sheer force or a lucky break
This article refers to Jobs’ Stanford commencement speech where he advised to follow your passion.
But he [himself] didn’t follow this simple advice. Apple Computer was decidedly not born out of passion, but instead was the result of a lucky break—a “small-time” scheme that unexpectedly took off.”
Similar to Malcolm Gladwell’s writings, this article points the arrow in the direction of greatness being just a lucky break. I, for the most part, agree. You only control so much, so make sure that what you control – you do a damn good job at it! While you’re at it – explore, try different thing, and learn as much as you can. In this quest your best weapon is likely your curiosity.