Why do we get scared after watching something paranormal or horror?

I wouldnt say thats generally the case. A person that has never challenged those fears might be impacted by the viewing of a horror movie for instance. My best friend and his girlfriend never watch horror related stuff ‚because it scares them‘. Which is fine and dandy. But I find it also rather difficult to one day have kids, without being able to differentiate between fiction and reality. Or even without wanting to gain that ability. Because, yeah, it would involve facing fears etc., leaving comfort zones etc. Bullshit.