I was sort of kidding, you know.
Anywho, if you've read back far enough, you'll know that Achilles does this from time to time in order to hook some naive and unfortunate believer so that he can reel them in, trap them and grind them into dust with his logic, which makes absolutely no sense, given that this is a subject with an illogical answer.
Now, I'll leave to your imagination what exactly this accomplishes. He seems to get off on it, though, so that's probably it.