Dean and Castiel in “Unfinished Business”

Dean

Look, I'll be the first to tell you that this little crusade of yours is nuts, but... I do know a little something about missing fathers.

Castiel

What do you mean?

Dean

I mean, there were times when I was looking for my dad when... all logic said that he was dead. But I knew, in my heart, that he was still alive. So, who cares what some Ninja Turtle says, Cas? What do you believe?

Castiel

I believe He's out there.

Dean

Good. Then go find Him.

Castiel

What about you?

Dean

What about me? I don't know. Honestly... I'm good. I can't believe I'm saying that, but I am, I'm... I'm really good.

Castiel

Even without your brother?

Dean

Especially without my brother. I mean, I spend so much time worrying about the son of a bitch. I mean, I've had more fun with you in the past twenty-four hours than I've had with Sam in years. And you're not that much fun. It's funny, you know, I've been so chained to my family, but now that I'm alone... hell, I'm happy.