I was in a Japanese classroom, and I heard a high-pitched roar from a distance. It was a Spinosaurus, and it immediately came running after me as I made a dash for the exit. The door was barricaded, and the Spinosaurus lunged at me, and I (out of desperation) threw a punch at it. I woke at that moment with my right fist held out. The dream was so real that my body had reacted to it.
Something in your past will force you to deal with it.