Movies desensitizing? Is it worth it?

Does watching a scary movie desensitize people, to the point where the more often you watch it the less scared you will be? Is it a good thing to desensitize yourself? I often thought it makes you more cynical and paranoid in life. I feel like i am too innocent for scary movies, they are all too scary for me and i dont want it to effect my personality in a negative way like i dont want to get ptsd from it. I dont watch anything scary and then i think will i be scared of anything thriller my whole life like this everyone will be fine and my cortisol levels will go up. I am definetly not a gryffindor.