Flashbacks are most likely to occur under emotional stress or at a time of altered ego functioning; they are often induced by conditions like fatigue, drunkenness, marihuana intoxication, and even meditative states.
Falling asleep is one of those times of consciousness change and diminished ego control; an increase in the hypnagogic imagery common at the edge of sleep often follows psychedelic drug use and can be regarded as a kind of flashback.
WAKE THE HELL UP ....
