I think flat round earthers are a really good case study on how good the human brain is in blocking out information it does not want to see. Like when you look at the chicago skyline from lake michigan, you sometimes see some of it which you shouldn't. Of course on a flat earth, you would see all of it all the time, but... it's always more important to find as many shaky arguments as possible so that as soon as someone calls you out on one, you can jump over to the next and never be confronted with the really difficult ones. When in doubt, change the subject to Sasquatch.