Many years ago, I had the same nightmare several times. I dreamed there were flying discs swarming through the halls of my first grade school. I interpreted these as UFOs for many years. Since then, I have come to the conclusion that they were drones in a premonition.
In the dream, I realized it was a dream and looked for ways to awaken me. I found my red wagon and struck my head with the handle until I woke up.
Unnerving.