Dean Winchester most definitely did not like Castiel when they first met. No, not one bit. Sure, the guy had pulled him out of the Pit; Dean would give him that much. But still, there was something about the deadpan holy tax accountant that rubbed him the wrong way, and for the life of him, Dean just couldn't figure out what that something was.

Maybe it was the fact that Castiel was an "Angel of the Lord," as he so flatly put it, because if that were true- if angels really existed- then God must exist, too. And if God were real, he had a hell of a lot to pay for in Dean's mind. All those long, painful years on the road hunting demons and vampires and things that go bump in the night, well, Dean could have used a little divine intervention or at least a sign that he wasn't alone, that what he was doing was right. Of course, he didn't get any help from his heavenly father, who seemed a bit too much like his earthly father for comfort. Whenever he needed someone, whenever he needed God- where was he? Where was he when Mary sat by Dean's bed at night, promising that angels were watching over them? Where was he when John had gotten so far lost in the hunt that Sam and Dean were left alone in yet another shady motel for three weeks straight? And where was he when Sam decided he had enough and left, leaving Dean alone? He didn't want to believe in God, because if God were real, then he was a real dick. If Dean had any faith left, he wasn't going to waste it on some absent higher power who sat by as Mary burned on the ceiling of the nursery all those years ago, who watched John become so obsessed over the Yellow-Eyed Demon that he forgot how to be a father, who let Sam die in some bastard demon's game, who ignored Dean as he was ripped to shreds by hellhounds and dragged to hell and back.

Dean didn't want to think that God was up in heaven watching good people get murdered, not batting an eye when the Winchesters had to bury yet another friend. He didn't want to believe in that, but if Castiel was telling the truth, which Dean could just feel that he was, then God was as real as the amulet he wore around his neck. And honestly, Dean wasn't ready to welcome him or that reality into his life, but Castiel and his "righteous mission" were going to force that very belief down his throat. Maybe that was why the holier-than-thou angel didn't sit well with Dean.

Or maybe it was the fact that Castiel had saved him from hell that had put the angel out of Dean's good graces from the start. Sure, Dean wanted to live; hell, he and Sammy had spent months just trying to get a little more time, and he was grateful to be alive and out of the Pit for good. He wanted to eat diner food with Sam in skivvy motel rooms, drive across the country in the Impala with Metallica blaring full volume, he even wanted to go back to ganking ghosts and shape shifters and all those sons of bitches. He wanted life to go back to normal- or at least as normal as it gets for a Winchester, that is. But he knew that after hell, well, nothing could be the same, The things he saw, the things he felt, the things he did- how could he go back to his former life like nothing had happened? He asked, begged, pleaded with himself to forget, but the pain was still there, lurking in the corners of his mind. He couldn't close his eyes because if he did, he'd find himself right back in the Pit; keeping his eyes open didn't help much either, because no matter how hard he tried, he couldn't shake the agony.

When he had made the deal so long ago, he accepted his fate. Everyone dies, and he'd rather be the one buried six feet under than Sam. He was going to hell, and that was it. He didn't want it, not really, but there was no way he could avoid it. When his time came and was dragged to hell, he gave in to it; Dean Winchester had met the end and there was no turning back, not this time. He didn't like it, and even though he'd rather sit through two weeks' worth of chick flicks before admitting it, he was more terrified of what was coming than he had ever been of anything ever before. That fear, of course, was well-founded because hell was, well, it was hell. Dean could feel the flames burning through his skin straight to his bones, sense the hellfire coursing through his veins- he was in utter agony, and he would have given anything for the torture to subside, even for a moment. On the rack, getting torn to shreds over and over, he would beg and plead for someone- anyone- to get him out; he tried for forty years, and no one came to his rescue. Then again, it's not like he felt as though he deserved to be saved, because in his mind, he didn't, especially not after becoming the monster he feared the most. But hell wore on him, and there was only so much suffering that one man, righteous or not, could handle. Dean had met his limit long ago and he wanted out, whether that meant returning to life or finally getting so completely engulfed by the inferno that there was nothing left to torture.

When he finally escaped the Pit, the Dean who had played pranks and could push his emotions down was long gone; in his place was a man so far beyond broken that even heaven couldn't put him together again. Honestly, he wasn't sure if he wanted to live, and he sure as hell didn't want to survive with the memories of hell seared permanently into his mind. But now, with God's almighty will laying out a path in front of him- a path to stop the very Apocalypse that he began when he started torturing innocent souls in hell- Dean didn't get the luxury of a choice. And that might have been why Dean couldn't stand Castiel, because it was his fault that he's back in the damn family business, his fault that he hadn't gotten pulled out of hell before he broke the first seal, his fault that he's going to have keep on living with those painful memories scorched into his mind. Dean wanted to hate Castiel for bringing him back, for not saving him in time, but he couldn't bring himself to completely hate the angel. No matter how hard living was now, it was better than being trapped in the literal hellhole, tormenting harmless souls. When it came down to it in the end, Dean was more thankful to Castiel than he was pissed- not by much, but by enough.

But that still left the question: why did Dean find it so hard to like the damn angel?

It took Dean three more meetings with Castiel before he realized the answer to the question that had been nagging at him since they first met, why he disliked the angel so much: Castiel knew him. He saw Dean Winchester for who he was, not who he pretended to be. When Castiel pulled him from hell, he saw Dean's past written all over his soul and who he was when no one was looking; he fought through the hellfire and saw the monster that Dean had become, the very beast that no one else had or would ever see if Dean had anything to say about it. And so he understood Dean, in a way that nobody else- not even Sam, his own flesh and blood- could even begin to. In those few short minutes when the righteous man and his savior angel first met face-to-face in that sigil-filled room, Castiel already had Dean Winchester pegged. He knew the part of him that was exposed like a raw nerve in hell; he saw the shattered and weary human who had already been through far too much. It weighed on Dean, wrecking him inside and out until he was the shell of the man he used to be; he believed only in his self-hatred and the fact that he didn't deserve to be saved. And Castiel knew that about him- a fact that took even Sam months to figure out. Castiel knew Dean, and that was why he disliked the angel.

Dean Winchester had spent his entire life building up walls to protect himself from the grief and sentiment that had broken so many hunters before him, and although his barricade hadn't stopped the pain, it kept Dean whole; no one had ever really gotten through to him before, not even Sam. Yet here he was, facing the fact that after a few brief meetings, Castiel, almighty angel of the Lord, had demolished those very walls that had been so impenetrable in the past. At first, every fiber of Dean's being screamed to push the angel away- no one can be trusted, especially not a soldier of an absent God- but as time passed, Dean came to realize one important detail: Castiel was a part of him, and Dean wasn't quite willing to shake him.

So despite the fact that Cas was an angel (and angels were notorious for being major dicks), and that he pulled him from the Pit after he made the mistake of setting the Apocalypse into motion, and that he completely disregarded Dean's fervent efforts to keep him away, Dean had made the decision to let the angel into his life. He may not trust him just yet, and hell, he may not even like the guy, but Dean knew enough to realize that he needed the angel in his life.

And so began the journey from the virtuous angel and his righteous charge to "I'll always come when you call," and "Cas, buddy, I need you."