Why would they want to destroy a world that they were a part of?

... I see. And you're not much older than she is. That must have been frightening. It's no wonder that she must feel the way you say she does; if everyone worries for her, in order to make up for that, she must care for others around her in kind.

Perhaps it was the world's enemies that had something to do with the time difference, then... I suppose it doesn't matter right now.