It's hard to get into peoples' heads, but in my experience, I've known people who were into conspiracy X, but did not want to admit that they believe in conspiracy X at first, so they told their friends that they were just joking, being edgy or learning more about it, etc.

After a while, they just grow tired of keeping up appearances, or maybe a famous person talks about conspiracy X, so they are no longer embarrassed by their belief, etc.