Yes, Red, I believe your grandfather offered you comfort. Whether it was his ghostly form, or memories or what doesn't matter. It was comfort that came out of a loving relationship. I do believe we retain a connection to our loved ones, that we carry them with us always. I do not know how to explain it, but then I can't explain the theory of relativity either, and that doesn't stop it from being true.
I have had a couple of dreams like that regarding people i have lost - my father, my best friend, etc. It is something that gives me hope, or something. I think of it as positive, anyway.
I also believe in precognition, so perhaps I am a little flakey in my beliefs. I used to read palms a lot, just to get to know people. Found out that it can be a little creepy how much one can learn from a person's hand - especially the ones who are very sceptical. Many times I amused myself by freaking out someone who thought I was just "reading the mark". comes in useful sometimes.