On the topic of contrition:
My MIL was openly hateful of me for the first 26 years of my marriage to her son. She believed that I married him "for his money" because I was raised in poverty, and he came from a middle class background.
The entire time we were married, we basically had no money. I put him through college, and then he and I both worked to put me through college. We made it paycheck to paycheck. He had no "money" when I married him, and we didn’t even buy our first home until we had been married 17 years.
Around our 26th anniversary, she was screaming at me (yet again) about what a gold digger I was. This was a thing with her when she got drunk. She screeched that I was only after him for his money, and I finally said, "Well, it’s been 26 years, and if he doesn’t cough it up soon I’m gonna leave him." She froze, and then started laughing. After that she started a slow thaw towards me.
Then her husband had a major accident, and I helped care for him. He passed away. Just two years later, she was diagnosed with terminal cancer, and I took care of her.
A few days before she passed, she said she had something important to say. She began to cry, and said, "40 years ago, if someone had told me I would have ended up loving you the way I do now, I would have told them they were lying. But I love you more than you can ever know, and I am so sorry for all the years I wasted being so cruel. I need you to know that."
We spent some moments holding each other, knowing forgiveness and love.
True contrition is felt deeply.