Think of the universe as a congenial but corrupt judge. Think of the miracle level as the bribe you are offering the judge. The judge would really like to take bribes from both you and your opponent, so will look for ways to say "ah, you got what you wanted and they got what they wanted." However, if the judge looks the miracles square in the eye and realizes that only one of you gets what you want, on some particular point, the judge will choose the higher bribe.
(The fact that the judge will grant both requests if you make it possible is important to me because I think players, and not just HGs, should be in a mode of "Yes, and" or "Yes, but" instead of "No" as much as possible. Help that poor judge get their money! They have little corrupt children and fancy cars to feed!)