This is such a good topic. Man.
I have to echo a lot of the things already stated, that people who are drawn to Mushing or RP in general are folks who have a desire for social connections that can be kept at arm's length. There is a safety to it. A sense that things cannot hurt you because of distance (Utter and completely false, but I think it is an easy lie to tell ourselves and hang onto despite multiple hurts happening) and that most alluring thing of all: The ability to be anything you want. In a table top setting I know I can have hesitancy, at first, from really sinking into character, because I am not a nine foot tall furry tornado of claws, teeth and rage and everyone there CAN SEE ME. Behind the screen, I can be anyone I want to be. And that is incredibly freeing. There is that wonderful ability to have intimacy without the risk of actual (again, this is typically untrue, but damn if I don't convince myself it is) vulnerability.
As for forgiveness... my own unique cocktail of social dysfunctions include a typically passive (and secretly competitive) personality, happy to follow a more dominant personality and generally do my best to absolutely please everyone as much as possible for as long as possible until I burn the fuck out or snap. I am also a wound collector. If someone hurts my feelings or treats me in a way I find objectionable, I will hold onto that and I will remember. I won't treat them any differently, but my eye is on them. And then one day, without warning, I will have had enough. And the Nice Me that is supportive and caring and energized and helpful turns into Raging Bitch and I usually go way too far. And I hold onto all that resentment that has been bubbling and brewing and I just see them as having victimized me for TOO LONG. 99% of the time, now I am self aware enough to stop this cycle before it gets too far. I try talking to people and being calm, or if I am going through a phase of being utterly out of touch with my emotions and am surprised into Rage, I generally pull myself out of the situation and quietly talk to someone to do a sanity check before I start projectile peasouping someone. The problem going forward is that even if I don't hulk out on someone, I tend to never forget the hurts. I will forgive them, I'll be nice and kind and supportive, but I will likely never trust them past that point. No one knows that but me. But it is there. And I wish it wasn't.
There is one particular grudge I really, really wish I could get over. This person was so toxic, so manipulative and just... gragh.. entitled. It still bugs the hell out of me. This person got me so mad that I literally just... I didn't recognize myself in the hateful spew of shit I went on. If someone brought her up on WORA or SWOFA, I would be there, screaming my hate like a freaking harpy. Saying the worst stuff because how DARE she be so evil!!! Said person is now an insanely successful, best-selling author who is working on all sorts of projects that I really want to read or check out, but I can't. Because while I am embarrassed by my behavior in the past, I still think she is the worst. Hearing her name still makes me twitch.
I really wish I could get over that. Because she has no idea, and my grudge is only hurting me.