I used to think that in xmas films the father christmas in them was the real one, who played himself everytime! Especially "santa claus the movie" for some reason :)
A childhood belief about father christmas

others believed things like this
- I used to believe that the "real" Santa Claus was at Macy's in New York City. All the rest were fakes. — Marcia
- I was told that for every christmas carol i sang before christmas time santa would give me one less present!— K
- I used to believe that, if God would die, Santa Claus would be boss.— Judith
- I used to believe that the Holy Trinity was Dad, God and Santa Claus!— Cathy P.
- When i was little, i thought Santa Claus was my grandfather— Junie
- Wehan I was little I used to confuse Jesus with God with Santa Claus.— Gui