Seems to me the interpretations I'm reading here overlook the most important aspect of the lyrics - the title. Referring to the Rosetta Stone points us to a junction place between languages/states of being (to incorporate the drug reference). Being Rosetta Stoned more than likely refers to a situation in which one has reached a point of crisis in which some 'code key' is required to break down the barriers between worlds/ languages but is unavailable. Hence the aliens, the drugs, the religion/ philosophy - all the oustide sources of thinking revolve around the speaker of this piece, yet ultimately remain inaccessible - perhaps partially because the key being used, perhaps drugs, is ultimately failing to provide the ultimate goal. Then again, I don't know the lyrics backword and forwards like some of yall.