Now he's narrating his own life

Today, when we were ready to get Ryder dressed, I told him to go into his room while I was still in our bathroom. A minute later I hear from the bedroom, "The door's closed, I wondered." What? So I go into the bedroom and see Ryder sitting on the floor staring at the closed door. I understand what he was getting at, but I'm not sure where that phrasing came from. It sounds like the narration from a book!