Here's the thing, in words of one syllable (the word "Hawking" has two, so excuse me that one): I think there was a Big Bang. Hawking thinks there was a Big Bang. I don't know for sure that there was a Big Bang. Hawking don't know for sure that there was a Big Bang (he'd tell you that if you asked him). It looks like there was a Big Bang to both of us. But we just don't know for sure. We have to look to science for the facts which point to a Big Bang. The facts do seem to point that way, big time. Could just be that the Big Bang did not take place, but I doubt that, and I think Hawking doubts that too. So there.

Hey, look at that ! Words of one syllable (except for "Hawking" - Stephen, may I call you "Steve"? Great name, you know!)