Sorry I couldn't get to this sooner - I've been hopped up on antibiodics for two days.
One little exchange stood out in my mind when rewatching (and rewatching) “Woman in White”. “What, you want some normal, apple pie life?” and Sam replies, “Not normal; safe.”
Does Sam truly believe that by leaving the “family business” he’ll be safe? For four years, we assume he’s been safe – no ghosts or demons haunting him, no trouble on campus, that sort of thing.
Sam doesn’t believe a nine year old should be given a .45 to protect itself from the monsters in the closet, even though Dean tells him that Sam should be afraid of the dark, because they know what’s in the dark. Most sane people would agree that child+guns=bad. But it was part of the ‘warrior upbringing’ that John Winchester gave his boys. Sam doesn’t believe that this life is what their mother would have wanted for them. I don’t think any mother would want their boys raised like Sam and Dean were.
We get another implication that Sam didn’t leave the family on good terms, not just saying his family wasn’t the Brady’s. Dean doesn’t know why Sam left for college – he accuses Sam of “running away”, and Sam says he was just going to college, and dad was the one who told him to stay gone.
So, why does Sam agree to go with Dean to find their father? Sam doesn’t believe that John is in any danger; he’s disappeared before and come home fine. He even tells Dean, “You don’t need my help,” and Dean agrees, but then says, “But I don’t want to.” I think that admission is what overrides Sam’s hesitation to go with his brother.
Sam’s hesitant to tell Dean he has a law school interview on Monday – why? Does he think Dean will tease him about it? Just more ammunition for Dean to get to him? Or does he want to keep his “former” life and his “current” life separate? He’s kept everything else from Dean and John.
Even though they haven’t spoken in four years, Sam trusts Dean – maybe he still has instincts that say ‘good/bad’? Maybe it was that admission of not wanting to do something on his own that got to Sam? Either way, he’s off with his brother, chiding “him and dad” about their credit card schemes. It’s obvious Sam doesn’t approve of the deception and credit card fraud, and by his stating, “You and Dad”, implies that he never had a part of it.
When Dean pulls out the fake ID, Sam looks disbelieving, and not without disapproval. More “illegal” stuff their family does in the name of business.
Sam takes a step toward Dean when he asks if Jessica knows what Sam has done, and says, “No, and she never will.” Definitely keeping his lives separate. Or keeping Jessica “safe”. Sam doesn’t believe he’s like Dean and John; he doesn’t want the life they have.
And this is the episode where Sam says that even if they find the thing that killed their mom, it won’t bring her back. Which, sadly, is true. Vengeance is what’s driving John now, or so we’re to believe. Twenty-two years of searching; Sam’s got to believe that it’s never going to happen.
Sam does something illegal – calling in the fake 911. Dean teases Sam about it, “That’s pretty illegal,” in a mocking tone, but it’s said with affection. I got the impression that Sam stayed on the fringes of the illegal activity, but wasn’t completely out of the loop.
Throughout this episode, you see Sam trying to pull back from Dean, reminding him about school and the interview. Dean either doesn’t remember, or pretends to remember. But by the end of the episode, Sam seems almost apologetic that he has to go back.
But when Jess is killed, all Sam can see/taste is revenge. “We’ve got work to do.” He learned the hard way that his new life wasn’t safe; that those he loved could still be hurt. And maybe he determined that doing something about it, tracking down the demon that killed Jess, was better than doing nothing.