How can someone possibly believe that the world is flat? Evidence our world is a sphere can be found everywhere you look, yet many insist that photos of a globe are lies. How can anyone believe the world is only a few thousand years old? There are literally mountains of evidence for an ancient planet 4.5 billion years old.
There are so many such beliefs floating about, and a surprising number of die-hard adherents to such fallacies. Yet they persist, and in this internet connected world some of these ideas flourish.
There are many reasons for such beliefs. Some occur as they seem right and are accepted without critical examination. Other beliefs are strongly held as a result of indoctrination from a young age. Once embedded deeply into a worldview such beliefs are very difficult to dislodge.
There is one factor that can be seen in most, if not all adherents to alternate worldviews… A lack of fundamental knowledge about how the world works, a lack of breadth to that knowledge. They have never reached a critical threshold of understanding, they never develop a good personal method of evaluating ideas, of testing against the evidence.
Once you reach a certain point in understanding our world, when you have learned enough to start making sense of that body of knowledge, you start seeing the connections, you gain an understanding of the whole. Proper understanding allows new ideas to be tested, to see how any new idea fits into the whole, to see the supporting connections.
True knowledge is not understanding one thing, but seeing how everything works together. It is not expertise in any one subject, but a body of knowledge from many subjects that is a sound foundation for further understanding.
Creationists, Flat Earthers, and mystics of many creeds never reach this threshold. They never gain this knowledge, or spend their time studying things that distract from reality. They never see our knowledge of the world as a whole, never understand the links that connect all of those separate theories and facts.
Without real understanding to test new ideas against it becomes easy to accept conspiracy theories, to see aliens, angels, or demons. Any mystery in the darkness becomes a monster to be feared. Without an understanding of the whole, how the real world works, anything can be seen as real, whatever idea that seems right is accepted.
Worse, without passing this threshold of knowledge you lose control, it becomes easy to surrender your free will to easy answers, to fear, to be manipulated by others.
Therein lies a major issue of our times, the vulnerability of so many to misinformation. The threshold does not just apply to information of the natural world, political, medical, and civic knowledge is just as critical.
It is common to find those who have accepted alternate worldviews so thoroughly that they are unable to fairly examine evidence that contradicts that view. If you must constantly invent reasons that allow you to dismiss evidence from the world around you, you might need to re-examine your basic views of the world.
It is not hard to pass the threshold, all it takes is an open mind and unbiased learning. There is no age limit, young and old alike can achieve this passage. Formal education, a college degree can allow this threshold to be passed more easily, while others learn on their own, from books, from nature, and from observation. A formal education is no guarantee either, a closed mind that refuses to see the real world will fail no matter what truth is presented.