exactly that's how I felt like! people around me would sometimes be scared sometimes, but after watching they wouldn't be traumatized as I did (like having nightmares as you did!) I also wonder why a lot of times.
I didn't think of it's because of empathy. Interesting thought! since I think I do have a good sense of empathy though.
I hope you could overcome horror movies too! at least I hope we could try not being traumatized. Cheers and thanks for the comment!