I saw a ghost once. It turned out it was me from the future.
"I came back in a time machine," said my future-ghost-self. "OooOOooooooo."
"What, ghosts need time machines?" I asked, "What's it made out of?"
"Ghost parts," said my future-ghost-self. "From cars in car accidents."
"What, car parts have ghosts?" I asked.
"Uh - yeah, pretty much everything has ghosts," said my future-ghost-self. "Anyway I've come back to warn you about something."
"But wait," I said, "Do the car parts die?"
"Because they were in a crash," said my future-ghost-self.
"Oh, come on," I said. "You mean if I throw a hammer at a wall and it crashes, then a little ghost hammer flies up to hammer heaven? That's ridiculous."
"Well it happens."
"But if the hammer is wood, wouldn't it be the ghost of a tree?"
"Look, do you want to hear this important warning or not?" asked my future-ghost-self.
"Nah, I'm not interested, piss off," I said. "If you can't get your facts right, why should I listen to your sob story?"
"Because it can save your life," said my future-ghost-self.
And that's when I kickboxed my future-ghost-self in the face.