The first Halloween, at the end when Sam Loomis (Donald Pleasance) emptied his revolver in MM and MM goes over the balcony, the said they were debating two reactions to making the movie. The first was when Sam ran to the balcony, only to see MM body gone (meaning he was still alive), he was to have a look of shock. The second reaction, which made it to the film, was more of “I knew he’d still be alive, wonder where he went....”. That reaction was much creepier to me.
I remember seeing that in a documentary of the making of the movie.
The 1978 movie
Halloween was the first R-rated movie I ever went to without an adult accompanying me. I took 3 Freshman girls that rode the school bus I drove and was their "adult" in the group.
I was 2 months shy of 17, and I think the usher either didn't notice or didn't care. The way the usher grinned at me, I think he might have let me in just for taking 3 girls to a horror movie!
When we left the movie theater, I had bruise impressions on my arms from all three girls grabbing me every time something scary either happened or they just thought something was going to happen. The first part of the film after the escape from the asylum was almost all "Made you jump!" moments that weren't anything scary.
That movie will always be one of my favorite memories from high school and one of my favorite horror films. Still get goosebumps from the piano music.