Does any one dream about dead relatives?

Ok I know that’s a wide open question so I’ll be more specific. My grandfather died 4 years ago. I have dreams with him in there, every so often. But he never says anything…he just smiles and is more or less in the background of things. I told this to my sister, and she said the exact same thing happens to her. It is so sad and so nice at the same time…I’m welling up as we speak.
Anyways, just wanted to know if this happens to anyone else, because when i wake up from these dreams, there isnt a more bittersweet feeling int the world.