You're right, but let me drop some 'pseudo'science on ya;
Entheogen's are a wide group of chemicals - of either endogenous (produced by our own brain) or exogenous (from other sources like cannabis, peyote, psychedelic mushrooms, DMT extracts, salvia divinorum) nature - that elicit a particular god-awe experience in mammals.
Its the same kick you get when you stand in a beautiful cathedral, before a thundering waterfall or gaze out the window of a jet plane at the vast expanse of clouds or stare into the deep blue sea or starry sky.
Other more widespread brain changes occur in deep meditative/trance dance/high states that can expand the senses beyond the physical self and trip off sensations of depersonalisation (loss of sense of self/body) and dissociation from reality.
Humanity, from the ancient traditions (from New world/Asiatic Shamans, Indian Sadhus (wondering ascetic stoner monks), witch doctors of the African continent) to new age LSD/DMT/Shroom trippers are all harnessing these fundamental brain states that the mainstream Western world tries to ignore.
Walk with us through the portals of our mind...
(Yeah time to pass the blunt)
Peace