My sister used to (might still) believe that she knew what Jesus's surname was. She thought it was Christ, which also lead to her thinking that it was his parents surname too!
A childhood belief about characters

others believed things like this
- I once asked my dad what Jesus' surname was, and he said it was 'Sinclair'.
I believed it for years!— Rebekah - I believed that Jesus Christ was the son of the Christ family, i.e., Mary and Joseph Christ.— David Araújo
- In a religious song, instead of “Jesus Christ” I heard “Cheese is Prize”— EJ
- Didn't Jesus say "And lead us not into Thames Station!"— Chris - Sheffield
- My parents told me that Jesus visited Santa Claus when he was dead for three days. — Rick Hamell
- i didn't beleive this, but a kid my sister knew thought if he screamed in a really high voice, he ran faster.Anon