I was only close to my Gram (Dad's mom) but she died when I was 14, I was taught to call my mom's parents Nana and Pappy but at some point, I started calling them Grandma and Grandpa or anything in between. I was taught to call my dad's dad, Gramps lol and since started call him sub-human so who knows, I guess anything will do. :) But I do understand the not being close I can relate.