My grandfather on Dad's side was Grandpa, and on Mom's side, he was Grandad! Guess I don't know about the Grandmothers - my Mom's Mom passed when I was 3 or so, so Dad's Mom was Grandma to me. Now MY grandchildren have had a bunch of Grandmothers, so they call me Grandma Joy to keep it straight! I loved my grandparents, and never objected to being called Grandma, but I know lots who don't want that moniker. I like to keep it simple and call it like it is!