Analysis of The Wall:
https://www.thewallanalysis.com/
https://www.angelfire.com/punk/kissme/wall.htm
https://en.wikipedia.org/wiki/The_Wall
The album turns full circle with its closing words "Isn't this where...", the first words of the phrase that begins the album, "...we came in?", with a continuation of the melody of the last song hinting at the cyclical nature of Waters' theme, and that the existential crisis at the heart of the album will never truly end.