Watching one of your parent die isn't something you just get over.

Somehow Sam is aware that Dean's words aren't for Lukas only. He now sees Dean as the little boy who never was, because he had to grow up too fast. He sees all the attention he was denied, while he tries to give it to Lukas. He observes the reassuring bond Dean is clumsily trying to establish with the boy. As though he meant it for Sam. Trying to compensate for all those years they've lost, for the cursed legacy their father left behind.

Unspoken words.

Hidden emotions.