I don't mean to be insulting or anything, but there are many first-semester philosophy students who could have made that observation without having to smoke anything.
Arthur hit the nail on the head. Alterered perceptions induced by artificial chemicals are just that: illusions. No "clarity" emerges from chemically induced alterations in neurotransmission, despite the illusory nature of such phenomena. The human mind and the neuronal networks that support it, work optimally in their natural state.