There's another argument for R=U that noone has mentioned yet. When Rinoa is posessed by Ultimecia a weird reaction occurs. This reaction never happens when ultimecia posess anyone else. Why? Because she is posessing herself, things get weird.
The most important argument for R=U tho is as rand says. This is a game. In the real world there are coincidences. Not in game worlds. In a game world everything that happens is the result of some guy actually adding it to the game. And people don't add things to games for no reason. Why did they put all these little hints in? Especially the "I want time to stop" "I want squalls gunblade to pierce my heart" "A sorceress needs a knight" things.
