As a child my worst nightmare was a huge smooth stone wheel that slowly rolled in empty space. And all I could do was to watch it as it slowly turned at the same spot. I dont recall if there was even black or white space. But what was very clear to me was that this was the real reality, and it had no end to it. I didn't get this as a thought of that this was all there is in eternity. I felt that this was what will be or is in eternity. That feeling of eternity made me terrified even after waking up.