Dan: There's absolutely no way in the whole world for John to prove his story. Just like there's no way for us to disprove it. No matter how outrageous we think it is, no matter how highly trained some of us think we are, there's absolutely no way to disprove it! My friend is either a caveman, a liar, or a nut. So while we're thinking about that, why don't we just go with it.