This is pretty offensive. It's like how many Americans don't know about their founding fathers. It doesn't mean they're "living under a rock". Nonsense.
But it's not. How the forget does someone not know about George Washington, or Benjamin Franklin? Did they even go to school? At all? And even more, that second statement probably isn't even true. That is literally the definition of living under a rock. Not knowing about something that's ubiquitous knowledge.