But he told you specifically what happened, and that triggered the memory.

[That's something to consider, at least, and Wash falls silent for a few moments, trying to see the thought to its logical conclusion.]

It's possible that similar content - seeing or hearing something that's in your memories, even if you don't know it is - is what triggers you. If that's the case, you probably have memories of Twilight Town. It would explain why the whole place is a trigger.

Though the only person you know of who'd know for sure is someone you don't want to ask. [Everything really does come back to Xehanort.]