Is OTHER wrong in the post ? POST : I know this sounds like one of those, "you know your NTA," post but I'm genuinely mixed about the situation and need to see what people think. If I get what I want, I'll delete this post.

For background history, my first memory is being woken up and told that my father is dead. I was not aware that he was dying. Maybe due to this, last words have always held importance to me. 

I was around 14 years old, possibly about to hit 15, when I learned that my grandfather went into the hospital for complications from a disease and that he wasn't expected to make it. He's the Grandpa on my father's side, and during my younger years I saw him as a father figure. He started traveling a ton in the years before his death, so I hadn't seen him for 4 or 5 years. I begged my mother to take me to see him. She said that we would. I reminded her multiple times and each time she said that we would. 

She never took me. She said, and I quote, "I didn't expect him to die." Keep in mind, we were told from the very beginning that he was on his deathbed. Afterwards I just couldn't stop thinking about how similar the situation was to my fathers death. Especially during my Grandpa's funeral.

I've always had a bit of rocky relationship with her, but that was the first time I thought that I hated my mother. I'm 16 now, and I've been attempting to actually talk to my mom more and develop a better relationship with her, but I just can't get over my grudge. I confronted her about it the other day. She denied that I ever told her we should see him, that alone made me mad as it's a plain lie. Then when I told her that, she says, "Sorry son, but you can't change the past." I'm not at all a crier, but that almost brought me to tears. How can you even say that?

Now here's the part where I wonder if I'm the asshole. I'm being light in the title when I say I despise my mother. I don't want to speak to her ever again after I turn 18. The real reason I'm trying to talk to her more is so I won't leave on a bad note, and just maybe, I could actually understand some of her actions. No luck so far. There's plenty of reasons to not like her, my grandfather was just the beginning. Even when I'm actually having a good conversation and we're laughing, I can't get it out of my head. I don't care about her at all and when she's old, I won't be there to take care of her. Despite that, I still wonder if I'm just being immature about the whole thing.