How did I not recognize your Phantasm avatar? Phantasm is one of my favorite cult movies ever! I have it on DVD and still watch it every so often.
At the time it seemed like in all the horror movies every time the protagonist tried to tell someone about the crazy stuff they'd seen, people would say things like "well you've been under a lot of stress" or "all you need is a good night's sleep" or something.
In phantasm, the kid tells his brother, and he's immediately like "Let me get my shotgun. We're going to kill that freak". It was awesome. :)