sam forgiving/being cool with the panic room later in the series makes me think abt this like.........bad-to-good conversion he puts himself through regarding his "nature" and the traits associated with it (most frustrating of which is how they're fine when associated with dean but not with him [ex. that one scene in s3, early s4]). the way i see it as time goes by especially post soulless era he has to figure out what traits he has that are Good and which ones are Bad, with dean as judge jury and executioner of what is Good or Bad + traits he shares with villains automatically being Bad. most apparent is how he responds to any suggestion that he has things in common with lucifer - he can't, because lucifer is Bad, and sam cannot be Bad. that coming on the heels of learning he was fed demon blood as a baby + dean being disturbed by his psychic abilities and his demon blood addiction + how he reacted in both scenarios where dean was dead (mystery spot and post-s3 finale) has him on pins and needles about being Good or Bad. i feel like black-and-white thinking is kind of necessary to be a hunter (is that a monster? yes? kill it) so it makes sense that, no matter how often sam tries to apply moral gray areas to others, he defaults to that base black-and-white, Good or Bad mentality for himself. dean locked him in the panic room because he was doing Bad Things, and since that was dean's attempt to stop him from doing Bad Things, it was a Good Thing in retrospect. this consistent pursuit of Goodness as not just a thing to do (saving people) but as a thing he is, like if he does enough Good Things he will finally become a Good Person and that'll cancel out all the Bad Things that made him a Bad Person (which includes things that were done to him, not things he actively did, and things he was coerced or tricked into). it's really fascinating and sad
