My mother passed away about 5 years ago, me taking care of her thru her cancer. In the hospital room, me attending to her, she asked me flat out, "How did you get to be this way?"...knowing I surely didn't get it from her. I answered, "It's my nature, Mom." Then I brought her to my home and took care of her till she passed, with great pain and difficulty.
Looking back, I realize my mother was abused as a child and young woman. She grew up in very difficult circumstances. But my growing up with her as my mother was a reflection of what she knew, how she knew to mother from her own upbringing. I got hit daily, and was verbally abused as well, even up into my college days when I'd come home for a visit. That said, she and my dad DID manage to send me to college, though they were very poor financially. So there is that to be grateful for.
In her older age, she began demanding acknowledgement of Mothers Day....also other holidays. She wanted the fiction of a loving mother-daughter relationship, which had never existed. I did accommodate her with the arbitrary gifts of flowers, or a dinner out with her and my other sister. It was easier to just go along.

Since her passing, I no longer feel the pain and resentment of my own history with her. I realize it made me what I am, why I made so many emotional mistakes in my own adult life, but I've come to terms with it.
It is good to have the perspective of time and age.