I used to have recurring nightmares as a child?

im thinking that it is probably due to everything you do not know. Such as ghosts. We dont know if they're real and people tend to freak out at a very young age. Eventually you start to think "no, they don't exist" as you grow up. You could have been scared of monsters, ghosts, and stuff like that. And yes, I have have recurring nightmares. Even if you didn't say it out loud, you were probably scared.