You present me with a dilemma: why did I begin your story and continue to read? Why did I start several others and not go on? As someone who likes to write but finds fiction challenging, I have to figure that out. I think it's the impossible proposition at the beginning--first of all he's Mr. Everything. That's already too big a concept for us to grasp, so we want to know more. But then, he has to think of something he doesn't know. Once again, we're stuck, with Mr. Everything.
I think it's the novelty and the pace--the story almost reads like a parable. And then the end rewards with that ridiculous last line. A great job. I think it's called talent :)