Flashbacks are very rare, possibly even mythological. (A psyconaut friend of mine has reported only one 'flashback'-- it was a fraction of a second on the bus

Flashbacks are very rare, possibly even mythological. (A psyconaut friend of mine has reported only one 'flashback'-- it was a fraction of a second on the bus when she thought her hair had turned into a snake.) There are some effects (often visual effects) that persist. See: http://en.wikipedia.org/wiki/Hallucinogen_persisting_perception_disorder http://en.wikipedia.org/wiki/Hallucinogen_persisting_percept...