You guys have it all wrong- these people don’t let old woulds fester. It’s not about actual hurt. It’s about winning the argument. They have to one-up you. When they run out of ammunition for the current fight, they have to reload with their reserve supply. It’s not about getting anything off their chest. It’s about saving face.
I also know plenty of men who do this. I couldn’t have a reasonable argument with my ex when I was upset about something because something happened last month that he never got over, and that is obviously more important that my current concern.
I don’t fucking get it, I don’t care, keep it the hell away from me.
tbh he played the victim a lot (perhaps this is a commonality in scorekeepers? more than gender anyway). He was not mentally healthy.
The title of this thread is making me a tad nauseated. 
J/K
Quasi
I have an ex-friend whose husband did this to an amazing level. He was about 55 when I last had contact with them and once he was telling a story- this person had just completely dicked him over and on and on and omg he couldn’t get over it and etc etc…I figured it was a mutual friend and that a recent business deal had gone bad. When I asked who it was, he remarked that I wouldn’t know him, it was 30 years prior. What? He was so pissed off at the retelling that it was impossible to know it was an old grudge that he was nursing. Talk about sick. He did it all the time and never forgot when someone “wronged” him.
I wasn’t a score keeper when I was young but I’m learning to be one. Fool me once …
I’ve met a few people who would like everyone around them to forget the past so they can use them over again. “Why are you bringing up that shit about me stealing money from you? I said I was sorry!”
I’m not a natural scorekeeper but, having a few in my life, I’ve learned how to pull any counter-example to whatever crap they’re pulling from the Pleistocene or from some distant corner of the Milky Way. Not when the crap they’re pulling is about me: in that case, what works is silently and politely waiting until they’re done, then going back to whatever I was saying before they interrumpted with their archaeological berating; when the counter-examples work well is when they’re complaining about a third party. Shuts them right up, when they’re saying something like, say, “oh, but side-of-the-family-I’m-not-in is so cold! Your cousins never call!” “When was the last time one of yours called? Invitations to baptisms don’t count, my side calls for those too.” Mind you, I have no idea how can my mother manage to work herself up about stuff that happened to her grandmother when the future-grandmother was nine, but she sure does.
Littlebro does it, but it’s financial stuff only. He keeps score of “how much gifts cost”. I’ve warned him that if he pulls that stuff with me, he can start taking care of his computer his own self.
My wifes family seems to do this. When my wife and her sister were kids, the sister would pull out a calculator to make sure they got the same value of presents at Christmas. My wife now keeps this in mind when buying stuff for our kids. I keep telling her that her sisters morals have no bearing on our family.
I’ve had to remind her that I don’t keep score and couldn’t care less about how much my brother had recieved or past ‘wrongs’ that were done to me.
I’m sure we are screwing up our kids, with me telling them to worry about their own ‘status’ and not worry about what others are doing and my wife desperately trying to make sure things are always fair/even.