To be honest, I really don't think that dreams 'mean' anything, but we put meaning to dreams just as we attribute meaning to anything and everything in our fully conscious state. It might even be that dreams are more our less a matter of our brains 'defragging' memories and such.
Interestingly, though, ever since I mentally awoke about a year+ ago, the apocalyptic dreams I used to have, completely ceased. With my worldview change, my dreams changed.