I was one of those people who didn't believe in ghosts until I experienced the most insane in my own home as a kid and it was a complete warning of a fire. A few days later one occurred in my home. My best friend as a kid died in a fire as it were.
There was also the most intense dream I had that was very profound and theological in nature. I still get shivers when I think of it.
Now, you might say the dream was somehow a figment of my imagination because my brain generated it. Though the theology wasn't at all related to what I was interested in at the time.
The experience I had as a teen is irrefutable, truly something out of a movie, I know what I saw, felt and smelled that day. To the extent that I asked my mother the next day if she experienced the same. It was no dream, I was awake.
A couple of days later a fire took out our place, the only room untouched was mine.
Now I am the type that always look to explain an experience, to this day I am a skeptic. Except I cannot deny that surreal experience I had many moons ago. It is fully unexplainable and I know what I experienced as it was multiple signs over a 15-20 minute period.