I actually watched the little video with Bill in it. Taken out of context, his remark seems stupid. OK, so Bill never learned that science pretty much knows where the moon came from. But I think (I hope) his point is that it is an endless argument. You can go on and on about one thing came from something else and there is no end. He is not really a scientist so he can't put this point using the right words. The fact is, our whole solar system came from dust from an exploded star. So, when Bill is told that he will reply "where did that come from?" and when you eventually get to the Big Bang, he might reply "how did that happen? How does existance itself exist?" and eventually we fall off the map of scientific knowledge completely. I believe this is what he means. So he does not know that we know where the moon came from. If you fault him for being uneducated, you will eventualy fault everyone.