It is a lot; it's easy to understand why Shinji never wanted to talk about his world now. But to have him apologize for--what, his experience? It's not even like he told her, the memory was just shoved into her brain by outside influences. If he'd had his way, Shinji surely would have kept it all to himself forever, wouldn't he?

"... I'm not sorry I saw it," she says quietly, but then frowns, and corrects herself, "--except that it's something you didn't want me to see. That part isn't right. But...." It's her turn to hesitate. Would he even understand what she's getting at? Would he close off again? "It's something that someone important to me had to endure, so... I'm glad I know a little bit about it now."