A lot of people see The Exorcist as a nightmare for mothers, but it's very much a nightmare for little kids, too. Unless you think being forced to stab your privates with a crucifix and growing a demon face sounds like a gentle daydream, that is. The idea that your body could simply be abducted and used like that is pretty horrible even to kids who think projectile vomiting and head-spinning sounds like fun.
And in the newer version, kids have the whole "spider-walking" scene to deal with, which will give you nightmares no matter how old you are.
