a note about Sam "leaving Dean."
I know there have been a thousand different essays on this, talking about how Sam always comes back, how it wasn't about getting away from Dean, it was about getting away from John and hunting, or about saving the world, and about how it was necessary for his development and sense of identity. I won't cover those (for now). This is about both the time he went to Stanford, and the time he went with Ruby. For this particular rant, I'm going to leave aside the fact that he went with Ruby to save six billion fucking innocent lives, not because "I want a piece o' dat demon ass, hurr durr durr," because that's for another time.
The thing about both situations is, Sam wasn't planning for that to happen. He never thought it would be a permanent thing. During Stanford, he intended to keep in touch with his family and visit them and maybe even have them come on campus every once in a while. You know, like normal people do. He never saw college as the "end" of anything-- it was a beginning. For the apocalypse, he didn't think that he would have to sacrifice his relationship with Dean to achieve his goal. He thought he could kill Lilith, save his brother the world, and have everything be okay. Yeah, his methods weren't the best. But hey, what does it matter if he becomes a monster? If he turns into the thing he fought so hard not to be? It's a small price to pay for the world. That's how he felt.
But do you know why things ended up happening the way that they did? The reason he chose to cut dies with his family and essentially ruin his brotherhood?
"If you walk out the door, don't you ever come back."
That's why. Those magic words. Tell me, have you ever seen anyone stay after an ultimatum like that? Would you ever expect them to? Because to the person on the receiving end, what that's saying to them is "I can't accept you anymore. I can't love what you've become. I would rather cut you out of my life completely than have you like this." Now, that might not be what they mean. In fact, it's probably not. It's probably something they said in anger and hurt, in the heat of the moment, before they could stop and think. But the other person doesn't know that. They don't know what you really mean.
So you have Sam, eighteen years old with a full fucking ride to Stanford, who is now realizing that his father would rather disown him than see him escape a life that was killing him from the inside and would probably lead to an early, violent death. All those years of never being good enough, never being the perfect soldier, never being the right kind of person, finally coming to a head. I can't accept who you are. You are not my son.
And then you have Sam, years later, desperately trying to do the right thing through the wrong means, willing to become the very thing he has hated so fervently for so long, if it means he can do this one thing. And he hears the same words. But this time, from the one person he has looked up to his entire life. Who he has always admired and loved and tried to be. You're a monster now. I don't recognize you. I would hunt you. I can't have you in my life. He doesn't know that Dean doesn't mean it. Because hey, it's not like Dean's wrong. He is a monster. A "whole new level of freak." He just never thought his big brother would be the one to hate him for it.
So you think it was selfish for Sam to go? I think it would be far more selfish to expect him to stay.