How much can you tease your brain?
I once really, genuinely, tried to believe that the Earth is flat (round). But failed because my eyes told me that the Sun goes down while according to official Flat Earth Society point of view, Sun never gets below Earth disk.
Yes, you might be surprised, but there is such a thing - a community of people who believe or claim to believe that the Earth is flat. They have a website, with live forum, articles and stuff.
I won't discuss if I think that they genuinely believe in it or if they do it "just for fun", but I want to tell you that I find it impressive that in modern world (since the website is in English, I assume that most members of this society are from US), there still are people who are not afraid to think against something what is "common sense" by definition of majority. After all, when we first heard about Quantum Theory, wasn't our first reaction "What a nonsense!"?
Once again, link to the official website: Flat Earth Society