I used to believe that Hosianna was a character from the Bible because of the line "Hosianna, Son of David!" in a religious hymn. Unfortunately, the religion class I attended only reinforced this belief: We were told that King David had many different children, and imagining the mysterious Hosianna as a less prominent son among several siblings made a lot of sense to me. It took a couple of years until my father found out about this belief of mine and set me straight.
A childhood belief about hymns

others believed things like this
- I thought that since my grandpa and my dad's names are both David, than David Bowie must be my aunt's son.Anon
- I believed that everytime I kissed my David Cassidy poster he'd feel it back home in Hollywood.— Marie M
- David Bowie - Jean Genie
"The Jean Genie lives on his back
The Jean Genie loves cheesy snacks"— Santa Puncher - I thought that Ted Bundy was a character on "Married With Children."— Patrick
- I used to belief sloths lived in trees outside my childhood home. My older sister told me so.Anon
- I used to belief that if you stood behind the TV, you would appear on the screen.— Gen Rodenis