true, the lyrics are from the Tibetan book of the dead. but john's intention for the song was to turn an acid trip into a song, so that you could trip without actually tripping. but yes, the lyrics are not acid related.
timothy leary would be proud of this thread 
Wrong. Here's the deal: Tomorrow Never Knows
"Tomorrow Never Knows" is the final track of The Beatles' 1966 studio album Revolver, but it was the first to be recorded for the album. Though the songwriting credit is Lennon-McCartney, the song was written primarily by John Lennon, closely adapted from Timothy Leary's book based on the Tibetan Book of the Dead. It is regarded as one of the first pieces of psychedelia, including highly compressed drums, reverse guitar, processed vocals and looped tape effects. Lennon told producer George Martin that he wished to sound as if he were the Dalai Lama singing from a mountain top. Geoff Emerick wired Lennon's voice through a Leslie speaker, thus obtaining the desired effect. (Lennon's earlier idea, to have a thousand Tibetan monks come to Abbey Road and chant on the record, was passed on as unfeasible.)
The song's lyrics dwell on spiritual aspects and are not readily interpreted, but the Indian philosophy behind the song is quite apparent[citation needed].
The title never actually appears in the song's lyrics, but was instead taken from Ringo Starr's interesting collection of malapropisms. Lennon chose to do this because he was embarrassed about the spiritual theme of the lyrics in the song, so he decided to give the song a throwaway title. The piece was originally titled "Mark I", although "The Void" was at one point a working title.
