Enabling circumstances are the circumstances that the hero creates or finds for himself; they are the circumstances that surround the hero at the beginning of the story and that allow him to maintain his flaw. Remember, the hero views his flaw as a defense mechanism, something necessary for his survival. Thus it's natural for the hero to seek out or create a set of circumstances (a job, a neighborhood, a set of friends, et al.) that enables him to maintain that critically important flaw.This isn't just talking about screen characters but people in real life. It figured into the cat lady story, and now it colors the way I see everybody, including myself.
The hero usually has a flaw at the beginning of the story. This flaw hinders him (or her) in some way, even if the hero doesn't realize what the flaw is--or that it is hindering him.That's humans in a nutshell.
The hero most often views his flaw as a defense mechanism he needs for his survival. The hero does not view his flaw as a flaw, but as a way of coping with life, as a behavior that protects his life metaphorically or perhaps even literally. That is why the hero has not already let go of his flaw--he actually does believe that he needs it.
Another interesting thing is the way the character's flaw molds his relationships. My new Facebook quote is: "There's a fine line between love and enabling." It means that in every relationship, you run the risk of reinforcing the preexisting character flaw of the other person or of yourself. This happens because each of us tends to mold the relationship to accommodate our own fatal flaw.