Delving into the semi-waking-semi-sleeping twilight world that one experiences when falling asleep, the author begins with a look at hypnagogic myoclonus-the muscle twitches experienced when one is drifting off to sleep, and Exploding Head Syndrome-loud noises and other brain sensations on falling asleep. The mental phenomena of hypnagogic vocalizations and imagery, dreamlets, and lucid dreaming are discussed, along with hypnopompic phenomena,...