I didn't get an apology for her part in the argument 24 years ago, but I didn't need that either. The simple truth is that I let that go 24 years ago like a typical spouse who's not mentally ill. I did my part for her, to let her heal and let go, and our conversations the next several days were very different. She wasn't on edge as much and she showed me more empathy for some things I'm dealing with. So in a way, I "won" as well by choosing not to play the blame game.
In principle I agree, and I was doing essentially that for many years (without really knowing what was going on). The problem is that now so many of my one-sided apologies are being used against me as evidence that I'm the deficient one who needs to change in order to fix things. And if I don't, it proves that I've not learned my lesson (her words) and therefore I'm the reason why we can't be close. So I'm really struggling with how to handle the blame in a way that a) defuses the situation and yet b) doesn't sow the seeds of the next conflict.
I have proposed an amnesty, in which all grudges before today are forgiven and forgotten, but she was quite astonished that I would think that we could go back to a romantic relationship so quickly.