Sam liked his life, generally.
Sure some classes were boring and some professors damn near infuriating but Sam had always enjoyed learning and this new life of his had surrounded him with more opportunities for that than he'd ever imagined he'd have.
The people around him were hungry for knowledge and improvement in a way he had always thought made him a freak. An outlier in a world where everyone else kept moving past the things that could have been better simply because there were better things to do.
All of the years of arguments and torn books and shunned and shamed ideas had left him angry and desperate with the sense that there was something wrong with him.
There was never any room for questions under Dad's roof, no matter which roof it was.
But he'd found his place here, where these people were just as eager and just as hungry as he was.
He'd found friends, real friends, that were his age and that he thought he could stay in contact with for more than a few months at a time.
He'd fallen in love.
Really, properly fallen in love.
They'd taken their time and started as friends and for the first time in his life Sam took his time falling in love because he knew that he could.
Jess would still be there to kiss tomorrow if he didn't do it tonight.
And that surety more than anything eased his anger.
He could spend his whole life angry at Dad for the way that he had raised him, and some part of him likely would, but it didn't matter anymore.
His life was here where books were sacred, and questions expected, and love could take its time, and nobody ever got to give him orders again.
He thought about the way the light seemed so much warmer when you got the chance to step out of the shadows. He thought of warmth, and love, and he thought of his brother.
He thought about how he knew that deep down this was all Dean had ever wanted.
As much as he scorned and jeered at all these 'boring white fence freaks', Sam knew that Dean desperately envied those lives.
All Dad had ever given them was fear and the dark and gun smoke but all Dean had ever wanted was love and the sun on his torn up skin.
Dean would never have those things. He was too afraid of losing whatever illusory affection Dad could scrounge out of the dirt for him. It was the only thing he'd ever known. The only thing he could count on.
Sam stood in the sunlight in a grassy quad and listened to the laughter of his friends and his first gentle love and deep in his heart he felt so bone crushingly sorry for him.
Dean had given everything he had to give Sam the chance to realize this life.
If Dean had never looked out for him and loved him and snuck him books from the library Sam would never have had the strength to leave.
Sam could leave because he knew that Dean, at least, would still love him.
Dean never had that guarantee.
And no book in the world could tell Sam how to save his brother from his own empty heart.