This so cracked me up. I knew an elderly man whose favorite wine was blackberry and I think it was from Manishevitz as well! It was in a tall square bottle. He would take out the bottle and have a small glass every night before bed. I also did the "polite" thing and joined him in it whenever I was there.
My 92-year-old Gram's favorite alcoholic drink is elderberry wine, which I'm pretty sure is a Manishevitz. The elderberry flavor is actually getting pretty hard to find, so luckily she also enjoys the Concord!