SUBREDDIT: r/relationships
TITLE: My mother [49 F] is angry with me [22 F] for not being sad about my grandfather's death.
POST: My maternal grandfather recently passed away. It came as a surprise, even though we knew he had poor health. (He smoke and drank a lot during his lifetime, and its effects really came out these past few years.)

When my mother told me, I just kind of received the news with an "Okay, I'm sorry." I think I was blank-faced, because my mother became angry with me and demanded to know why I wasn't sad enough, why I wasn't crying, how could I not be upset over my own grandfather's death. She kept berating and yelling at me until my father intervened. Things have been awkward since, and I still think she's angry at me.

I feel awful about the whole situation. The truth is that although I feel sorry he died, I'm not that sad. I feel like a stranger died and not my grandfather. When other people's relatives die, they are devastated, but I feel relatively little. I am also confused and upset by my mother's behavior. My mother did not have a good relationship with her father (my grandfather) and part of the reason I didn't have a close relationship with him is that she only let me rarely see him. Also, she used to complain before that he was not a nice man and was physically and financially abusive to his wife and kids, so I've always had a negative opinion of him. But she's extremely upset by his death and I don't know how to handle it.
TL;DR: 
Grandfather died, and I don't really feel sad about his death because I wasn't really close to him. Mother gets angry at me for my lack of reaction. I feel guilty and frustrated.