I was sort of prepared for his questions. He might ask, "Does God have feet?" I knew that.
I also knew he might get into why cycles. "Is the Earth round?" Whywhywhywhywhy etc.
I was not prepared for the random questions. That is, questions that make sense and have a context but the context is Not Now.
Example: it's bedtime. Ok, it's way past bedtime. He's not asleep. As usual. I go in to hug him and tell him to be quiet and he asks, "What color is PufflePuff?" I can't remember. I say maybe purple. He says, "That makes sense because they both start with P." "It's Hufflepuff, honey." "Right, Pufflepuff."
"Are they the best wizards?" Then I explain about jocks in Griffindor and brains in Ravenclaw and baddies in Sytherin. I don't know what to say about Hufflepuff. It doesn't matter. He's over it. I walk away and two minutes later I hear: "E I E I Oh..."