A few months ago, I saw someone who was not there. I woke up in the middle of the night and saw a woman with long hair and a long dress leaning over the bed. She was not frightening or threatening in any way. I gradually realized that I was seeing her features more clearly than I should be able to, given how dark the room was. Then she faded away. I am as certain that I was awake then as I am ever certain that I am awake.