I posted some hallucinations I had to /r/glitch_in_the_matrix and figured it would be interesting to hear other people's stories about hallucinations. Here's my stories if you want to read them.

About 5 years ago I experienced 3 strange events within a week of each other. I'll make this clear... I had never done any drugs. In fact, I had never smoked a cigarette, had only had a few beers in my life, and I had never even drank a cup of coffee. I have no medical conditions and in the 5 years since have no experienced any strange events or symptoms.

Lack of sleep is the only factor here that could even remotely possibly cause these events. This month was during a period when I was going to a lot of parties (at which I was always sober). I probably slept 6 hours a night on average. I was no sleep deprived though. I mean, I have worse sleeping hours now than I did then. Anyway, here are the stories in order. They get progressively weirder.

STORY #1
I was working as an usher at a theater and it was an extremely slow day. There were literally no customers around 90% of the day and only a few employees anywhere near. Walking down the hallway at one point I hear a whistle behind me that sounded like a "Yoohoo!" whistle. I turned around, but no one was anywhere nearby... and it sounded like it had come from directly behind me. I went about my day but kept hearing the same whistle probably once every 5 minutes and every time I turned around no one was there. It was too close for someone far away to be fucking with me. Eventually I brushed it off as nothing. If it weren't for the next two hallucinations I wouldn't have given it any more thought.

STORY #2
I was sitting across from a friend of mine at Denny's chatting and waiting for our food. The waiter brought us our plates and as he walked up I noticed something odd about my plate of cheesy bacon fries... it looked like it had hair on it. Not just a little. A lot! The waiter set it down in front of me and I kinda just stared in confusion and disgust as the waiter walked away and my friend started eating. It seemed to be cat hair and it was pretty much covering the food. My friend said, "You okay there?" I looked up and said, "What the fuck is this!?" Confused she said, "Uh... what's wrong with it?" I almost laughed, "What's wrong with it!? How about it's covered in cat hair!" A little freaked out, she slowly said, "No... it isn't." I looked down. No more cat hair on it. That event really freaked me out.

STORY #3
One night, around midnight, my friend and I were walking around downtown. I was still 20 and I hadn't had any drinks that night. Neither had my friend. As we walked past a particular bar I saw three athletic looking men standing on the left side of the sidewalk smoking. My friend was closest to them as we walked by. The guy in the middle glanced up at us, my friend looked at him and suddenly became very angry. He threw a left hook and knocked the guy onto his back in the street. The two friends jumped back in surprise.
My friend went back to normal composure and kept walking, never having missed a step. In shock, I continued walking as well and just stared at my friend. After 10 or so seconds, he looked at me and asked why I was staring at him. I stopped walking, no longer in shock and just confused now. "I don't know, maybe because you just punched someone right in the face for no reason?" Then I looked back to see the three guys standing there smoking still as if nothing happened. Nothing had happened. My friend was sure I was high as shit.

What's strangest to me is that all three of these events happened with a week or so of each other. There was no common factor that I can pinpoint. Just hallucinations for no perceivable reason. They never happened before that and have not happened in the 5 years since.