Board Thread:General Discussion/@comment-26006155-20181229180615/@comment-32182236-20190101020722

Yes, Chara was indeed the example. But then, Chara also knew this, else their plan couldn't have happened before. Therefore, the humans up above still know this, this became common knowledge up there. The monsters couldn't have known it at first, after all. Unless Gaster figured it out and proved it somehow. (And before you say that's easy because he's human by your theory.. He still can't prove it that way without giving away that he's human.)