A small example, not related to this, but when I started DJing about 15 years ago, I put on a party that was a warm-up party for a bigger night. I told John Digweed (who was running the bigger party) about it. John Digweed was one of the worlds biggest DJs at that point, and as 'luck' would have it he was releasing a new mix CD. So the world's music press was there to interview him.
He came down to my party with the world's press and suddenly my first ever party was in magazines across the globe. I started getting offers of gigs all over the world after that. There were much better DJs around (I was pretty average back then), but I'd had the stroke of luck which ended up in a pretty successful 'career' (I put it in quotes because I always treated it as a hobby, but by most people's measurements it was pretty successful).
Knowledge and skill is obviously important, but luck definitely plays a role, especially when it comes to areas of life that very few succeed in.