I've had this experience of knowing that I was dreaming, but I don't remember the details, but rather the feeling, which was very comforting in the situation. I know this is off topic, I'm sorry but I feel the need to report. One time I had sleep paralysis... I couldn't move or speak, and in my mind there was a figure standing next to the bed and I was trying to scream for help, and my body felt like it was being crushed. I always remember this distressing situation.