personal/family/religious beliefs - we get shaped with beliefs from young ages and from stories and things people can develop a superstitious fear.
their own experiences - some people believe that some <em>paranormal activities</em> have happened to them and it can develop a fear depending on how much it scares them.
their ideas of what can happen - people have the tendency to think about the future and replay or create scenarios in their heads and that's how an irrational fear can start.
