Some frikking 50's or 60's movie about mummies coming back to life and killing people.
When I was told to go to bed, the hallway was dark, so I ran 100 miles per hour so the mummy won't get me!

There was also this other one. I had to look it up. (20 million miles to earth -1957)
https://www.imdb.com/title/tt0050084/

It still gives me the creeps just thinking about it.

You?

One where everyone got rid of their weapons and the whole world lived in complete peace and harmony.

I had nightmares for weeks!

I was always scaring the shit out of myself watching scary movies as a kid... my cousins and I were really into them. Anything would scare me. Nightmare on Elm Street franchise being our favorite. Seems really silly now.

(April 26, 2021 at 3:19 am)vulcanlogician Wrote: I was always scaring the shit out of myself watching scary movies as a kid... my cousins and I were really into them. Anything would scare me. Nightmare on Elm Street franchise being our favorite. Seems really silly now.

Something like that. I remember when I was a kid talking with a friend who said how he saw in the video store a VHS cover of a movie called “Children of the Corn” and now he was afraid every time when he drove near the cornfields at night because he was afraid of these mutant kids that live in the cornfields. Too bad he didn’t watch the actual movie, but just the cover, because it’s very lame and had nothing to do with some bloodthirsty mutant kids living in cornfields, but something else—I’m not even sure exactly what: just some hippies doing something lame (?).

Pinocchio.

Boru

I also remember seeing "The Thing" (early 80's) at the cinemas with a mate. (we were adults though, 18 or 19)
The cinema was empty except for us to. We had a joint while watching.

We both shat bricks!

For me, it had to be the 1935 version of The Last Days of Pompeii. I didn't actually see the film, but when I was only five or six years old (1954) the movie was going to be featured on Saturday night TV. I saw the previews around supper time in which the Pompeiians were running through the streets while Vesuvius erupted. Some of them were on fire. That night I awoke in terror from a Technicolor nightmare in which I was a victim of the disaster. It took my mother about an hour to calm me down and get me to go back to bed. 

Actually when I was I kid I watched that movie "Teeth" about vagina dentata and I was so scared of women biting me with their vaginas. Especially women with skirts that they would lift it and then the vagina will devour me.

Soylent Green (1973) My dad had already spoilered me on this film before we watched it together. The whole reason we watched it was because he had made reference jokingly to the end and I had no clue what he was talking about. Anyway, it's been a while, but knowing the ending conclusion beforehand, I remember getting very upset and feeling anxiously nihilistic during the people-dumptruck scene. This big dumptruck just plowing through the crowded city streets, shoveling people back into the waiting bed of the truck. The incomprehensible desire of survival that erases boundaries, society, community, and morals and the merciless, faceless, hopeless arm of bureaucracy feeding the maw of humanity.

My mother also showed me the original Pet Sematary when I was 10 or 11 after finishing the book. At the time, it was hard to get me reading books so, when we figured out I was an edgelord and liked horror things, she allowed me to read Stephen King and Clive Barker just to get me to do the freeform book reports I was told to do for school. Anyway, watching Pet Sematary after finishing the book was my reward(as was watching Cujo and Hellraiser after finishing their novel counterparts). I still remember being viscerally disturbed by all the Zelda scenes.

Some of the drivers education movies were pretty gruesome. Red Asphalt comes to mind.