I was trying to find a film of the tribes of the Pacific Ocean area, but I bumbed into a documentary about the flat Earth believers. I thought the idea of a flat Earth had stayed in the past and didn't know it had emerged again during this decade. My observations are mostly based on the Netflix documentary Behind the curve but I also read a news article about the situation in Finland in 2019 and searched The Flat Earth Society web site. 
 The Flat Earth is a theory of the Earth being a disk and about 70% of the members believe there's a dome on top of it creating the sky. The community has made theme appropriate music, books, radio shows, registration plates, dating web sites and everyday items. They have meetings in big cities and had the first international conference in 2018 which was shown in the film. Nasa is usually viewed as an arcenemy since it is believed no one has ever been to space and all Nasa is telling are lies. 
 It seems the society is mainly focused in the United States but it might have supporters in other parts of the world as well. In the news article from Iltalehti they said there is a Finnish Facebook group with 1600 members but the writer doubted they are all real supporters.
 In all interviews and person introductions conspiracy theories were brought up either by being the reason for first discovering the flat Earth theory or the individuals believed in a lot of different conspiracy theories. Mark Sargent was featured throughout the film and is considered one of the lead characters in the Flat Earth Society. 
 Sargent works closely with Patricia Steere who makes podcasts concerning the flat Earth related topics. In the documentary Sargent and Steere visited a Nasa museum where their sole purpose seemed to be to despise and criticise their "enemy". At one point Steere told she doesn't believe in bomb attacks unless her own foot explodes with it. Steere admitted people in the community make conspiracy theories about her and she has no way of proving them wrong. She has been blamed for steering people away and accused of being a CIA agent since the last three letters of her name suggest it. 
 A person called Matt was introduced who clearly wants to be some kind of a dictator or a leader in the community. He feels he invented the theory and started the community. He feels threathened by everyone else who have become motivational speakers or leading characters in The Flat Earth Society. When Matt was asked to be part of the documentary he send a list of demands which included he getting 5000 dollars, having 12% of the proceeds of the film and that the film should recognize Mark Sargent as an impostor and agent sent by Hollywood who are working with the government. Two days before the international conference Matt posted a video explaining to people how it is organized by the government and how all the speakers would be fake agents. The members of the Society seemed to be easily converted in different directions since a lot of people who had bought a ticket to the conference didn't show up even though they couldn't get a refund. 
 The film consisted of a lot of theories and "scientific" test results the members were using as proof but most of them were fake or failed. Even after failing the tests they wanted to continue and either repeat the test differently or find proof elsewhere. This shows that they weren't making the experiments objectively. They had a final result in mind they wanted to achieve. As the result wasn't satisfying they weren't open to change their point of view which is against the idea of science as an unbiased way of shaping your views through proof. As the science professors and psychologists said in the documentary, there are a lot of theories including the imposter syndrome, Dunning-Kruger effect and confirmation bias which could explain the behaviour of the flat Earth believers. 
 I feel that as long as it doesn't hurt anybody or affect anyone else they can continue what they are doing. But as someone pointed out in the documentary, the members are trying to convert other people and once it reaches the political level there are going to be problems. Once important decision makers believe one theory they might end up doubting other scientific proofs as well. 
 I was amazed many of the believers had cut off connections to family and loved ones since they received disapproval or negative feedback concerning the flat Earth theory. This means that they are tied to the community even more and might not want to give it up even if they changed their view or it was unconditionally proven that the Earth is round. 
 I believe most of the flat Earth Society members get caught up in all the information available of conspiracy theories and especially in the internet it is easy to pretend to be a professional and introduce fake and made up theories, test results and facts. They probably feel the need to belong to a community and find people who think alike. Since it is hard to understand concepts like space and gravity, one of the reasons for believing in the theory might be a natural never ending need to explain and understand things so that the human mind can process them. 
 I tried to stay as objective as possible but as the documentary progressed I couldn't help but form conclusions and biases. I learned that it is quite hard to be unbiased and to try to understand the minds of others and their way of thinking and building thoughts when it comes to more extreme and unconventional questions like believing in the flat Earth. 

Sources:

Netflix Documentary: Behind the curve (2018)
Iltalehti news article: https://www.iltalehti.fi/kotimaa/a/0eca9456-3450-435b-a9f6-b328477d247e
The Flat Earth Society web site: https://www.tfes.org/