"Hey---" Startled out of the darkening spiral of his thoughts, Cloud ducked his head out of pure reflex, though not far enough to avoid getting his hair ruffled. Maybe he didn't really want to avoid it, but he still frowned up at Zack, even if it didn't quite contain the usual amount of displeasure.

"... he is?" Cloud paused, thought of what his older self had said, and then he nodded slowly, "... right, he would be. That is weird." And it was, because Zack just wasn't younger than him.

Of course, for him he wasn't, but Cloud wasn't going to think too much about that again.

"... I guess," he agreed softly, frowning a little. "... you know, I think Zack. Um, the one I know, is older than you too."

He would be, wouldn't he, since he'd lived through all of this too...