Why am I still not "sad" about my grandfathers death while everyone else is?

Ok I am a 17 year old female and today is the 1 year anniversary since my grandfather passed away. Every weekend me and my dad would go to his house in the morning and spend time with him doing all sorts of things. He was still very active even though he had cancer. However when I was told he passed the day of I was kind of upset but any days after I never really felt anything. The majority of my family is still like gutted from this and I feel weird and wrong cause I'm not feeling anything about it. I figured there could be like delayed grief but its been a year and I just feel nothing. I don't know what's wrong with me. I still have sympathy with my grieving family members but like I said, I myself don't feel anything on the topic and I don't know what's wrong with me. If anyone can try explaining why this is or if there's just something wrong with me that'd be cool. Thanks for your time