I’ve seen Wolf Creek. It’s a great suspenseful film. It’s not really scary on any visceral psychologically scarring level, though.
It certainly makes you recall things that are gruesome but I don’t rock back and forth in fear at that.
My point was more that the horror films mates always claimed to be the scariest were the ones they saw when they were in school. The Thing, for example, had that “Oh my god it’s so scary” thing over and over from everyone. I didn’t see it until I was 20 or something and by then it was basically just a suspense-filled action sci-fi. Same sort of thing with Alien.