No, arksys, I have not met anyone who professes that they believe "the earth is flat" or that there is an "end of the earth" somewhere.
However, there are "backwards" behaving people who practice "wrong thinking," toward other humans and towards "Nature."
You see, we are in "a fix," so to speak, in this world because of people who are "not playing with a full deck," so to speak..
I may sound like I am negative toward those people who are not intelligent or smart enough, or whatever the problem is, to except facts, but I am sort of discouraged with "out of touch" thinking people. I have to force myself to be more patient with those who are less fortunate that myself, or you. There will always be people who do not know the truth, or want to know or except the truth.
Good question, arksys.