John listened with his eyes closed, reliving in Dean's words his own experiences, for they'd held a similar flow to them when John was enough himself to tell the demons or souls torturing exactly what he'd thought of them. Even now, thinking about the way his son had been broken, it woke up those places John tried to hard to forget as much as possible, the parts that knew a thousands ways to make suffering last – woke them up in fury that those crimes against his child needed repaid. But they couldn't be, not ever.
And hearing Dean admit he felt wrong some days was the hardest part. He couldn't say Dean wasn't a monster, not because he thought his son was, because he didn't – the faith John couldn't have in himself, he still had in Dean. It was that saying so was hypocritical and dismissive, because it was the feeling that John lived with every single day and saying it wasn't true didn't change it.
All he could do was let Dean know he wasn't alone in the feeling, that there was one person who understood. Well, he could do that and one other thing.
"I know, son, I know," he said, then roughly pulled Dean into a hug.