Ehem... I think that this thread deserves this masterpiece of Lennon...
I am the Walrus
The story behind the nonsensical lyrics:
John found out that many of their songs are being analised for subliminal messages and hidden lyrics. His response was to write a song with lyrics that dont make any sense whatsoever. Supposedly he said "Let the fuckers figure this one out!" after he wrote it. He was also on LSD, which explains the video, I guess.