Sam wants a better life for his brother than he feels he can give him, and thinks back to how Dean could have been happier.
As his mind gradually floated back to consciousness, Sam became aware of the comfortingly normal sounds that encircled him, the self-same sounds that had defined his childhood; the thrum of the engine, the beat of the music, the smell of petrol, worn leather and long-digested food.
These elements, just like those of a giant jigsaw puzzle combined perfectly to form the Impala, the only stable home he could remember, an island of shelter and security in the sea of horrors that constituted his daily life.
It was the only place where he could abandon himself to sleep without the ever present fear of danger catching him unawares, its steel walls shielding him from harm.
While he lingered here within her, he felt safe and loved, the car providing the security and the man sitting next to him in the driving seat, the love.
Sam knew Dean considered him to be the empathic, gentle, morally-challenged component of their two man team, but Sam was well aware of a fluctuating darkness within him.
He was only able to recall snippets of his year bereft of a soul, but he was conscious that the sexually uninhibited maniac and the cold-blooded killer he had been then were intrinsically a part of him, perhaps buried down deep now that he had his soul back, nonetheless part of him.
In fact he found his body craving sex in a way it hadn't before, obviously remembering the enhanced use that Robo-Sam had made of it, he reflected ruefully.
He stole a glance at his brother from under his eye-lashes. He wasn't worthy of being at Dean's side.
Dean, contrary to himself was one big dispenser of love. He could lavish affection continuously and unendingly on the persons he cared about. He certainly deserved more than a crappy mixed-up brother like Sam to bestow that love upon.
Sam's thoughts drifted back to when he was at Stanford.
He'd been so sure of himself then, sure of what he wanted from life, no hunting, no monsters, only normal, making a life with Jessica, becoming a lawyer.
Helping people in a different way, from the Halls of Justice instead of in a graveyard burning bones. However it had all been a farce.
Even then he'd been surrounded by demons, as Lucifer had so gleefully shown him during that terrifying prelude to his jump into the Cage.
When Dean had appeared that night at his flat and told him Dad had disappeared on a hunting trip, Sam had instinctively understood that his time at Stanford was over.
He'd tried to shut John and Dean out of his university life believing that out of sight was out of mind, but when he'd set eyes on his big brother, the magnetic force that connected him to Dean had blazed into full force once more, and with the subsequent death of Jessica all his dreams and aspirations for "normal" had burned to ashes along with her.
There you go again, Sam, he chided himself, always moaning and groaning about yourself instead of considering Dean's needs and aspirations. He deserves something more in his life that to be eternally looking out for you and worrying about what will happen when that crumbling wall in your freaky brain finally collapses.
Images suddenly flooded Sam's mind of the people they'd encountered during their life on the road.
There had been many women amongst them, girls that Dean could have loved and been happy with if he hadn't had to be forever concentrated on saving Sam's skinny ass.
What was her name, he mused to himself. Right, Haley, that was it.
Dean had been instantly attracted to her, not unexpectedly as she was his female counterpart, strong, courageous, understanding and most importantly, the protector of her younger siblings, a fact that Dean could immediately relate to.
He toyed for a moment with the idea of Dean and Haley as a couple, maybe alongside that of himself and Jessica, and smiled at the idea of them in suburbia next door to one another, each with a couple of kids of their own, living the apple-pie life; laughing, loving and being loved.
Yeah, right, if they hadn't been multi-cursed Winchester brothers!
His mind went back to another girl they'd encountered, Andrea.
With her Dean had also felt an instant sympathy, her life marked by the tragedy of a dead husband and father.
She too could have been a loving companion for Dean, his brother's protective instincts already awakened towards her young son Lucas, but the on-going search for their father had nipped that right in the bud.
Then of course there had been Jo.
She'd had a monumental crush on Dean but he viewed her as little sister material, though with time it might have led to something more if her tremendous sacrifice hadn't ended her young life so heartbreakingly.
She could have been good for Dean, able to understand and accompany him in the hunting life he led.
Even when Sam had thought to make something good of his own death in the Cage by having his big brother promise to go and live a normal safe life with Lisa, the only woman he seemed to have any hope of having a long-term relationship with, it had turned out badly for Dean.
She'd been possessed by a demon, resulting in Dean having Castiel scrub her memories, something that Dean had been so up-tight about that he'd refused any discussion, threatening Sam himself with dire consequences if he ever brought up the subject again.
Sam sighed, his mind silently repeating over and over that Dean deserved more than to pass his life protecting his trouble-magnet little brother.
"Sam!" Dean's husky voice ousted him from his reverie. "Stop brooding! Your thought-waves are drowning me in a sea of depression. I don't know, nor do I want to know what's passing through that freaky brain of yours, but if your guilt trip concerns me, just know this.
I'm driving my Baby, singing along to the greatest songs around and I've got my soul-filled little brother in the passenger seat, so at this moment I wouldn't change what I have for anything else in the world. You hear me, Sammy? Answer yes or no, dude."
Sam lips curled up in a half-smile as he locked glances with his brother. "Yeah. I hear you, Dean. No more brooding."
"Right," was the caustic reply. "I'll believe THAT when I see it!"