I tend not to hold grudges because I don't see the point of holding anger. If someone wrongs me I might increase the distance between us socially or not trust them with certain things if I feel it would be unwise to continue. Sometimes there needs to be some kind of reconciliation for things to be close again. I've definitely stopped being friends with people for reasons that were unlikely to change or where it wasn't worth continuing, but it's very hard for me to stay mad at them or wish them ill. Even the people who've done awful things to me or who are now contemptible in many respects, I just kind of hope they do better in the future, far away from me.

I've never considered this to have anything to do with my adhd, but maybe? It would definitely be something more complicated than just forgetting though.