Luck happens. But it happens to some people more than others.
It is comfortable to believe that luck is something that happens to us, instead of something we can control — to an extent, at least.
When a writer finally has a bestseller, people say he is lucky. As if luck had anything to do with the thousands of hours he spent writing before his first big hit.
When a young, fresh graduate gets a well-paid job, people say she is lucky. As if luck had anything to do with all the thousands of hours she spent studying and developing her skills to make herself a better hire.
Working hard, building that door, is not a guarantee of success. But not doing the job certainly is a guarantee that luck will not come knocking at your door. After all, there is no door to knock on.