I also randomly came across a video with a woman who mentioned that she's a flatearther. I had heard about this idea briefly in the past, but I think know it's a "real thing". She seemed so serious and convinced that it's true. I looked into it and found there there are really a lot of people that talk about it. I spent a few hours watching different videos about how people explain this idea. There are so many holes in their logic and it is very unscientific. One of the funniest things is how much time they spend trying to explain how photos of the earth for space are all a hoax. They think it's a massive conspiracy between all the governments and space programs of the world. It was interesting to hear what absurd things people think it. It was also interesting to see what rebuttal videos people have made explaining how real science works. I've been all the way around the world. It's not flat.