Recent dreams containing sloped

I suddenly was at the bottom of a hill it wasnt too tall but it sloped up a bit. i walked up it and realized it was a graveyard. i walked around a bit and found a coffin that was on a stand kind of like the ones that are used to display the remains of the loved one who passed away. i had a feeling that i had to open it and i did. when i opened the coffin i saw my grandpa who passed away in 2004 and he got up and was walking around talking to me but i dont remember what he said. we were walking around and then suddenly he disappeared. i ran to the coffin and there was nothing there. somehow my grandpa disappeared. then i woke up and my dream ended. i never dreamed about it again but its bothered me a bit, wondering what happened and what it meant.