I accidently bumped into him at the Borders Bookstore in San Rafael back in the late 90's. I was looking at the new hardbound SciFi books and he was looking at the Star Wars books on the top shelf. I just said "excuse me" and he said "no problem" and we returned to our tasks.
My son used to wait on him at a restaurant in Chicago when he came by to visit his now wife. My son, being a professional actor, had to use his best skills to treat him as just another customer