The question remains—have you ever met such a person?
I have not—and I don’t know anyone else who has....
Yes, I have. Not many but a few. One was a friend of my nephew's. And he was not joking around, LARPING, trolling, he really believes the Earth is flat and would send my nephew all sorts of links and videos in email and on FB trying to prove it. I met him in person a couple of times, nice guy but also believed the Moon landings were fake and the Earth is only 6,000 years old.
I think we have a handful of Flat Eather's here on FR as well.