Gee, why didn't I think of that?

Courtesy of theologian extraordinaire Agonaces of Susa from fundie megasite christianforums.com:

"According to mainstream scientists and chronologists, based on uranium-lead series radiometric dating of moon rocks the Earth is only 4.6 billion years old therefore years did not exist before that because the Earth wasn't orbiting the Sun." [emphasis added]

  I really wish I had a witty retort here, but I'm dumbstruck at the sheer ignorance.