Struggle with not experiencing grief

I found out 15 minutes before I left for a networking fair today that my grandfather passed away last night. I honestly didn't really know him, he was a veteran and very closed off even though I stayed with them for a month every summer in my child/tween years.

I am 20 and this is the first time someone I know has died. I know grief comes in different ways for everyone but it's almost as if I am experiencing the grief for my grandmother and mother, not for my grandfather himself. Which I feel so guilty about because I did love him.

It's not that I don't feel anything for him, I do I just feel like it's not enough. That I can go through my day with ease and I'm not feeling what I think grief is supposed to feel like. I do wonder if it's almost a stage of shock, because i've never experienced a close death I don't know if I just can't understand he's gone and that's why it's not hitting me.

The funeral is set for next week and I'm sure things will change going forward, just wondering if this is a normal experience in my situation because most of what you hear about grief is the opposite.