When I was little, I didn't know that "want" used to mean "need" as in "needy," so I thought that when you said, "The Lord is My Shepherd, I shall not want," you didn't want the Lord being your Shepherd & wished he would just go away.
I also thought that at Christmastime you sang, "Round yon virgin," because she was round, because she was pregnant with Jesus.
I also thought that the choir at Compline was singing about "God the Holy Parakeet." I still don't really know what a paraclete is.
A childhood belief about hymns

others believed things like this
- When Madonna sang "let the choir sing" in "Like a Prayer", I thought she was singing "love by proxy"— Kristen
- for the longest time every i used to think that Prince's "Raspberry Barret" said "round merry go round"— lin
- I thought that after the resurrection Jesus became the Holy Ghost.— Meowpossum
- I used to think the song"jesus, oh what a wonderful child so holy, meek and mild" was "so holy, Mickey Mouse"— Stephani
- I thought the Holy Ghost was the ghost of the Virgin Mary.— Texas granny
- I used to use the basketball pump in the air because I thought I was donating fresh air to the needy.— Emily