Connected worlds. Tidus listens without knowing where the story may go, or what it means, without a guess. It didn't sound anything like Zanarkand and Spira; two separate worlds in a sense, but not to the extent of actually being real on both sides. Watching Roland as he speaks, leans back his head and closes his eyes; meets his glace with a perplexed and puzzled face.

"Then... what happened to your soulmate? Did he get flung to your world?"

What happens to one, happens to the other. What else is there, that that could mean? Did they just trade places? Was that it? There's a lot missing, whether Roland knows the actual story himself or not.