Songfacts®:

• This is one of Neil Young's strangest, most surreal songs. Despite a few decades of scrutiny by Young fans and critics, it continues to elude all attempts at rationalization. It's likely there's no concrete underlying meaning at all, as Young himself is quoted in Shakey as saying he had no intended meaning for it to begin.
  
  "Some do, some don't," Young said in regards to whether or not his songs have a definitive meaning behind them (specifically mentioning "Last Trip to Tulsa" in the discussion). "It's not important to me."
• In the song, Young seems to be recounting past lives or identities. He identifies himself as having been a cab driver, a woman, and a folk singer. He also mentions having once been asleep, driving down the freeway, and chopping down a palm tree. There are frequent mentions of cars, roads, and travels.
  
  The most popular interpretation among fans has been that the song is about drugs - specifically LSD. There are mentions of yellow servicemen, green gasoline, Indians trying on Young's clothes, and other assorted oddities, so it's not a big reach to connect the two. Still, the usual "it's drugs" line doesn't seem to fit Young's modus operandi. Though he's been open about his own drug use, he's also never been one to glorify it. While he certainly may have dreamed the song up while stoned, it seems a little too obvious and unimaginative to have the song actually being about some drug experience.
• The song starts with discussions of driving a cab and then ends with him dropping a palm tree down on a friend's back as the man walks to his Cadillac. This occurs after Young's admission that he's been cutting at the tree for 87 years.
  
  Young turns a lot of phrases that seem like they have some deeper meaning, such as:
  
  So I unlocked your mind, you know
  To see what I could see
  If you guarantee the postage
  I'll mail you back the key
  
  Despite these gems, the song as a whole simply doesn't give itself up to any kind of cohesive interpretation.
  
  By all appearances, and by Young's own account, any deeper meaning arose from the darker corners of Young's mind, and not from any purposeful meaning. It's a stream-of-consciousness song. This fact can be maddening to fans who want a concrete story. On the plus side, though, listeners are free to shape the song in any way they choose.
• I used to be a folk singer keeping managers alive
  When you saw me on a corner and told me I was jive
  So I unlocked your mind to see what I could see
  If you guarantee the postage, I'll mail you back the key
  
  This verse refers to Young's 1965 experience in Toronto when he 20 years old and still trying to break through as a professional musician. Toronto was a rough, competitive music scene, and one that liked to stick to what it knew. A clear dividing line existed between the folk and rock communities, with Young being one of the few who openly appreciated and played both genres.
  
  Young has always been difficult to categorize. It's one of the things that has made him an iconic singer-songwriter with one of the most devoted fan bases in music. In those days, though, it just meant that he couldn't find anyone to pay him to play.
  
  His band at that time was 4 To Go. They played folk rock, which was a hard sell simply because the general city culture was so cleanly divided between the two genres. For most people, you were either folk or you were rock, and no mixing was allowed. They got together with high ambitions, especially on Young' part, as he'd known from the time he was a teen that he had no other ambition in life than to be a musician. It wasn't in the cards, though. 4 To Go never even played a show. They rehearsed like pros, and Young had a manager who tried to get him opportunities, but it went absolutely nowhere.
  
  Though frustrating, it proved to be a creatively formative event. Young started going deeper into folk styling and started writing deeply personal, raw songs with a unique poetic voice inspired in part by Bob Dylan's lyrical style.