The ones that did not draw attention to themselves and kept quiet about the things they saw would be able to escape the notice of those who would be looking out for those who possessed such potential.
Even if they were an ordinary person without such abilities, they could have some relatives or acquaintances who were a part of the supernatural world.
Some ordinary people came to know of the supernatural world through various experiences they experienced or through those they were related to, but they would soon learn about the taboos of the supernatural world.
Either they would learn to follow how things were supposed to work and they would keep quiet about such things or they would ignore it and they would choose to talk about it.
Those who chose to talk about it and tried to spread such information never ended well, especially if their case was quite severe.
