John Lennon even fought back at the allegations that the song was about doing drugs. He said that the song was simply inspired by a picture his son Julian drew that portrayed his friend Lucy in a childlike surreal manner.
Lennon also said that the song was about his future wife, Yoko Ono.
“It was purely unconscious that it came out to be LSD,” said Lennon. “Until somebody pointed it out, I never even thought of it. […] The imagery was Alice in the boat. And also the image of this female who would come and save me. This secret love that was going to come one day. So it turned out to be Yoko, though, and I hadn’t met Yoko then. But she was my imaginary girl that we all have.”
We don’t really doubt that Lennon was honest about the song’s initial inspiration. However, it’s clear that the song is a very poetic (and musically sound) ode to the psychedelic substance that he and the rest of the band regularly engaged in. Regardless of what the BBC and more conservative listeners thought of the song at the time, it’s still a legendary piece of work by The Beatles today.