Your worst nightmare?

I used to have the nightmare about opening your mouth to scream and nothing coming out all of the time. Then, when I was in my early teens I had falled asleep on the couch watching a movie and woke up to see a man standing in the doorway between the kitchen and den of my house. He had forced open the back door and was there to rob us. I screamed so loud and so long that the guy ran away and my father jumped out of bed and ran outside to try to catch him. Having proven that I would be able to scream if necessary, I never had that dream again.