It really depends on how much they're talked about! I had a grandfather who died when I was seven but had lost his mind to dementia by the time I was born, and while I knew he was my grandfather, I don't know if he ever got a title indicating as such. If he did I've forgotten it. (An extenuating factor, though, is that I later found out he was probably abusive to my father when he was growing up, so....)