After sinking many hours into Dark Souls, I've come to the realization that the story is actually very complex, even if it's hidden or muddied most of the time. Even the multiplayer aspects of the game have an in-world explanation which ties into the universe.
This makes me wonder about other things which never seemed to "fit" except as a game mechanic. Is there such an in-game, world-relevant explanation for the fog covering doors which the player must choose to "traverse the white light" through?
I always thought it was just a technique to prevent the player from leaving once a boss battle had begun, but now I'm thinking maybe there's some hidden intricacy to it that I've missed. This thought is enhanced by the fact that the fog does not always block the path to a boss; very often it simply leads to another area and immediately dissipates when the player crosses it.