It's not impossible for someone to make something up intending it to be a myth and then have it either A: turn out to be true. Or B: have someone else come in and make it a reality. Don't Get me wrong, I don't believe that Santa exists, but like any good scientist, the reason I don't believe is because there isn't any compelling evidence to believe he does. I'm not going to eliminate the possibility that such evidence may become available in the future. Long story short, super -blam!-ing hard to prove a negative.