My greatest epiphanies to solve complex problems that I had been spending great mental energy on always occur in that time right when I fall asleep in the sliver of space between consciousness and unconsciousness when you are floating between worlds. All of the sudden the answer shocks me awake like a lightening bolt, as the answer is always so stunning in its elegant simplicity
"Thomas Edison has attributed many of his insights into his experiments and new discoveries to a state of awareness and thinking he reached when entering what is known as a hypnogogic state. Hypnagogia is the a transitional state between wakefulness to sleep. The hypnagogic state of consciousness arrives at a demarcation just at the onset of sleep. ... Edison would generally hold two steel balls in both hands when he was preparing to sleep and was challenged by a daunting large problem. Some naps he would be sitting upright in a chair. Sitting up made it a bit harder for him to fully sleep allowing him to stay lightly conscious during these sessions. On the floor he placed directly below his closed hands metal saucers. The premise was simple, as he entered into the hypnogogic state, the body generally goes through a series of muscle reactions from a loosening to a sort of paralysis. In this transition Edison would drop the steel balls and they would crash to the floor, hitting the metal saucers for added effect and produce loud sound to awaken him. He would then be awakened by the sound and have a ready pad and pencil to record anything that he was thinking of just before being awakened."
Thomas Edison's Secret Trick to Maximize His Creativity by Falling Asleep