I used to have a recurrent nightmare up to the age of about five. It was as though i was constantly moving forward toward the narrow end of a funnel, but never getting there. The walls of the funnel were dull mixed swirling colours in constant motion. They were exactly like what you got if you mixed different colours of plasticine or play-dough together. In the end, I got used to it, and was able to bring on the image voluntarily without any fear.
Very much later in life, I looked back at this, and I wonder to this day if it was a latent memory of my being born.