When I was about 13 years old, my whole family used to camp out on the floor in our living room using sleeping bags, just for fun. One night, I had a bad fever that I didn't know I actually had, and I awoke in the middle of the night. I looked at the center of the room and I saw a rock with a snake moving over it. I didn't panic, I simply looked over at my mother and said, "There's a snake in the middle of the room." She sat up and looked around, and told me there wasn't and to go back to sleep. Apparently I did as I was told because I don't remember anything else until waking up.
On many occasions I have had a certain hallucination where I feel as though there is a ball of yarn in my hand that is growing. It terrifies me beyond belief and I end up crying about it, even to this day (although it's only happened once or twice in my teen years). While this has happened, I have also seen two large doors with chains on them. I later learned people describe this place as "the rift" between dimensions. Supposedly if you go through the door, you die. Lucky me.