If there is a common theme emerging from this thread, it may be about the degree to which our parents put their own needs ahead of their children’s that impacts our capacity/willingness for gratitude, forgiveness or resolution. Every child is entitled to be the center of the universe, the focus of their parent’s attention and interest. As parents, we all falter from time to time and of course eventually we provide our kids the needed challenges and frustrations to help them grow into adulthood. But when the balance is out of whack and the parent’s needs regularly and profoundly supersede their child’s - that’s difficult to forgive and forget.
I also think it’s likely that when a parent was like that when their children were young, that parent is likely to be similarly needy as they age. I think adult children of neglectful parents who maintain or renew a connection with their parents often (not always I suppose) find themselves still dealing with their parent’s narcissism, the parent still unable to put their child’s needs ahead of (or on par with) their own.
That said, I think in healthy relationships adult children eventually take on caring for their parents and looking out for them much in the way they did for us as children. In healthy relationships that’s done with joy as demonstrated by some of those in this thread. For others who are conflicted (like I was with my dad) it comes with a mix of obligation, desire to resolve, and a touch of resentment.