@VulgarKitten I'm kinda with @Arkandel on this one.
For instance, there's like... very few? people in this hobby that I actively, persistently, dislike. I could count them on a hand and have fingers left over. There's Rex/Sovereign, Jeurg, a chick who seemed to make it her life's mission to make me miserable OOC for no reason I could ever fathom other than that her life had taken a turn for the suck (which I could still empathize with) and a chick from Shang made entirely out of the crazy sauce on a level that's just whooooooaaaaaaa man look at ALLLLLLLLLLLLL of those colors. (Neither of the women post here.) But that's really it, and I don't have to deal with them much, if ever.
The people I argue with tooth and nail here from time to time I don't actually hold any ill will toward, which I think is the key thing. It isn't so much being desensitized as it is not feeling the need to hold grudges.
I remember shit, but it only tends to surface in a 'waaaaaaaaitaminnit... ' way when I see some kind of inherent contradiction (which is what I think you were aiming for here?) or, more often, to remind myself to be a little cautious or 'clarity first' around <person> because they don't like <subject> and I should avoid it around them (or conversely, they tend to enjoy <subject> I dislike and I need to make it clear to them I'm not interested in that particular joyride).
OK, I also remember shit when it's stupidly obscure and funny, like in the wayback SWOFA days when Lethe claimed to be a swarm of sentient cats. (Whyyyyyyy is that still in my brain? I dunno, but it still makes me giggle.)
There is stuff around these parts that will still piss me off. It's pretty rare, though. The creepy rape thing a month or so ago, for example, didn't really bug me, beyond the extra moment it took to register, "Did I really read what I think I just read? Whuuuuuuuuuuuut." Usually, the only things that actually piss me off are when I see something that makes me want to tear out my hair because I can't tell if someone is genuinely clueless or being deliberately obtuse to be a jackass. (Considering how often both happen around here, uh... it's surprising I still have hair? Or blood pressure that doesn't require medication? 
)
I've been posting on these places since an unholy forever ago, though. I actually found a few scratch pad text files of posts recently when doing a computer backup, and... goddamn, yeah, I've actually mellowed a lot.
I would have wanted to punch c.2001-2003 me right in the damn mouth and wince hard when I think about it. More than I do about anything anyone else has ever said, really.
Either way it's the wisest route to just not get/remain involved with the game.
