I was curious after reading your comment since the article I had seen earlier had identified the metaphor about aging, and I ran across a pretty in depth exploration of the song that paints a more complex picture. Looks like we’re both sort of right.
Part of the song was designed to be nonsensical, but there are parts that are inspired by the death of a friend, two acid trips with John and Yoko, and John said some of the lyrics that originally didn’t make sense took on a new meaning when sewn into the final song.
I could look for another example of a song without controversial messaging, but I think we both got the point that each other was getting at. Thanks for being an awesome person to discuss music with today!