Me, too.
I thought it was probably about the Catholic Blessed Virgin Mary but McCartney said it was about his mother named Mary. Even creepier, then, for a pop song.
I thought it was about smoking dope, you know, Mary Jane Wanna.
For decades, I thought this song was about the Blessed Mother, the mother of Jesus.
But then I learned that Paul was having a difficult time in his life, and his late mother, Mary, appeared to him in a dream and told him, “Let it be. Just let it be.”