The final chapter in the "Halloween" movie series, the eleventh I believe, is due out soon which will make a total of eleven of them I haven't seen!  As well as none of the Freddy Kruger or Friday the 13th movies either!  I see a lot of movies but I don't do horror.
Still they are a very successful genre, costing little to make and making millions in profit.  What do fans of horror have that I lack?
A recent study says one reason is that some people enjoy feeling more intense emotions, which is called "need for affect," and the people with this desire tend to like horror movies.
Psychologists say those who enjoy scary movies often like the feelings they get afterwards--making it through a safe yet scary activity  results in feelings of confidence, competence, accomplishment, and success

Scientists add that for some, there is no fun in being scared.  Sociologist Margee Kerr says, "There are folks who have had a bad experience with horror movies or scary content and associate all things scary with negativity...it's basic fear conditioning, for them, it's just not fun and never has been."   And that sounds a lot like me! (Refinery 29)