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 the dreaming mind's use of Familiarity and Context to fool the dreamer. Dreams proper, are also looked into. Finally, the author presents his ideas on waking hallucinations, and presents some famous fiction author's writings on hypnagogia.