I used to believe that Goria en Exelcis Deo (the carol) was actually Gloria in A Shell Station. I was always fairly confused as to why, during Christmas Mass, we sang about my Aunt Gloria getting gas. I would sing the lyrics quite loudly in church.
A childhood belief about hymns

others believed things like this
- I was told that for every christmas carol i sang before christmas time santa would give me one less present!— K
- I used to think that church songs were pop music. Well, we did sing them in church every week...— Roxy
- I was sad for many years because my aunt once told me I would go to hell for farting in church!— Tara
- When Madonna sang "let the choir sing" in "Like a Prayer", I thought she was singing "love by proxy"— Kristen
- Billy Squire sang about "My Kind of Lover". My wife sang about "My Candelabra"— Wailerman
- I used to believe that the sky is just a very thin blue egg shell— Alan