ok, i watched the weirdest weastern ever it had a white guy that hung with the indians and drank this weird stuff that brings out your inner demon. this one evil shaman and the white guy go up through caves in this mountain and enter this one room where they both drink the weird stuff to get the meaning of the universe or something like that whitch is a bunch of snakes and bugs everywhere? plz help???
Sounds like "Altered States", but if it is you either only watched that scene, missed the point, or both. It's a metaphysical sci-fi film about exploring the collective unconscious, cellular memory and our deepest, basest fears.
It's quite silly at times, but also quite powerful at others.