Does anyone else’s nparent have frequent memory lapses?

I think part of the reason my nmom doesn’t understand why both of her children are in therapy and diagnosed with c-PTSD is because she literally doesn’t remember what she did. And I’m not trying to apologize for her behavior or make excuses, but I’m wondering if anyone knows why this happens? Does their own brain protect them from themselves as well? I think part of the reason my nmom avoids hard discussions (or reacts poorly) is because she can’t remember and knows she can’t remember and she doesn’t want to admit that. I think blackout rage is so frequent and common, it’s just apart of her existence and it’s normal to her. Anyone else notice this?