In an earlier draft, he was just curious, but later I revised it so that he was retrieving things that Dean probably shouldn't have thrown away. In either case, the letter completely broadsided him. Hehe, I love that line--in my head, John was totally all Keep both hands on the wheel at all times until they came across a pack of werewolves and had to shoot them while getting the hell out of there, which was when he revised it.

Thank you for reading.