Since elementary school he's been coming home, grinning after a fight, and you don't understand why he likes to get hurt. Sometimes he kicks ass, and sometimes he gets his ass kicked. But either way it's like he won. Broken noses and bloody knuckles. You wish you weren't used to the sight.
He goes around breaking girls hearts as if he doesn't know what it's like to be used and discarded. You see them at school, still doodling "Dean Winchester" in their notebook like they still might get him back. They have no idea that in a few days he'll be in a new town with a new girl, and it'll be like he never knew them. Because he's not looking for love, he's looking for a distraction.
He's always out on hunts, and you know, now, what that means. He says he kills evil things to save people. But when he's too drunk to remember, he says he wants to kill himself. Who would he be saving, then?
He still has his faith in John, and you'll never understand because you've spent your whole life putting your faith in him. And you are starting to realize that's where you both went wrong. Because he's put his faith in a broken man, and that only meant he was breaking himself. You don't want to become that. You don't want to follow them down that path.
He has nightmares and you pretend not to notice. He doesn't cry out when he dreams, but you can hear his breaths quicken, and you can see his fingers grasping at the sheets for something he'll never reach. You want to help him, but he won't let you. You wish he would talk to you, but he wakes up silently, evens out his breathing, and relaxes his grip. You can't tell if he ever goes back to sleep, but either way the silence is deafening.
Another broken promise from John, and he acts like he doesn't care. But you know it's killing him, and you want to kill John for it.
You know he'd rather you break his bones than his heart, but you don't see any other options. You can't stay here, anymore. You can't live this life that he says he loves so much. You have to go, and you know he won't come with. You wish you didn't feel so much like your father, right now.
You now understand just how broken he was. Selling your soul is as low as you can get. You wish you hadn't been the reason- that you hadn't been the gasoline to the fire he was setting himself. "I can fix this..." You say. "I can save him." You think you can piece him back together, one shattered piece at a time. If you can just keep him around a little longer...
When he comes back it's worse. He's with you again, and you're glad, but he's not the same. And neither are you. The boys you once were are gone. You're men, now. Yet you still childishly hold on to the idea that you can save him, and he holds on to the idea that he can't be saved.
You can tell that Ben and Lisa changed him. He's better, now. You spent your whole life trying to do what they did in just a year. You wish that he had stayed with them, but you know it was your own fault he left. He was always going to choose you. Maybe he hasn't changed that much.
He's a whole different person after Purgatory. You can't keep up with how much he's changed in the last 8 years. You see how much Castiel has damaged him. You still can't believe he allowed the angel to get that close. Dean doesn't do that. That's what you do. You wish you could save Castiel, or at least help Dean cope with the loss. But you can't. Once again, you feel like everyone can change Dean but you.
After all these years, this is the man you're left with. You're not even sure who he is anymore. Is he still your brother? Is he still Dean? You wish you could say that his demonic side has been subdued, but you'll never be sure. At times, you can almost believe he's still young, still watching you like a hawk because you were the only thing he had to worry about. But other times, you can see his age. All those years of pain and torture and failure show through a goofy grin and a stupid joke. And then, even worse, sometimes you can see the evil. The Mark of Cain seems to be a permanent fixture in your life, now. And the demon inside him is here to stay until you fix it. If you can fix it. You wish you knew how. You wish you could have your brother back.