[ Jack and Dean had a highly contentious relationship from the start and now toward the end, although they've made their peace. He may have lost his rights to be family the way he was before he killed Mary, but he and Dean did manage to bond on the road to Adam and when he was preparing the bomb. He felt thankful that they came to a respectful place and he was ready to die.

But Dean never wanted to be that person for him, so Sam stepped up instead. Jack's past the feelings of pain and rejection that had for him when he was younger. He understands how complicated emotions can be. ]

No, it is you, just you in the future. Whatever happened with the Darkness, you pushed through it, all of you, like you always do.

[ That's the thing he admires about his family. Everything they've gone through, all the hardships and ups and downs, and they still fight, they still survive. It's why he wants to be strong like them too, why he hasn't given up yet. ]

Castiel, there is nothing that you can't overcome. I've seen it.