According to Darabont, it's not a matter of going out and doing X, Y, and Z, and then all of a sudden you're a filmmaker. He says it takes "instinct, talent, effort, persistence, and a belief in yourself" -- intangible things that either can't be learned or aren't as straightforward as walking up on a stage and receiving a piece of paper that will get you where you want to go.
A film career is not necessarily something you earn with your diploma at film school. A career is built on an endless chain of flugey circumstances generated by your efforts and your persistence. Luck has a lot to do with it, but you manufacture your own luck by working your ass off for it.