What movie did you watch as I kid which you shouldn't have?
My dads brother visited us one time - when I was around 7 years old - and they sent me to bed and watched a movie together on TV. I'm not sure where my mom was, perhaps taking care of my little brother, but I quietly went down the stairs and saw them watching the movie, and I stayed very quietly so they would not know I'm there.
It was a Bruce Lee movie, "The Big Boss (1971)". In that movie Bruce works at a ice factory and his boss kills some people and puts them into the ice. That's not the worst of it. They then have those big ice blocks and a big blade saw and that saw cuts the big blocks into smaller peaces. It also cuts those bodies in the ice blocks into smaller pieces.
I couldn't believe what I saw and went back upstairs and couldn't fall asleep. I never told my parents.
The Neverending Story: STARTS with a horse DYING FROM SADNESS and the movie is about existence being devoured by nothingness.
Nightmare on Elm Street: where the fuck were my parents?!
Time Bandits: the cages floating in the void, the dwarves being chased down a corridor, the parents die to evil at the end...don't they? Ambiguous existential dread all around this one.
The Thing: no clear childhood memories or nightmares but I know I saw it before I was 10.