I used to think "Dashing through the snow in a one horse open sleigh..." was "Dashing through the snow in a one horse soap and sleigh..." and my dad didn't miss the opportunity to humiliate me about it, either. LOL.
A childhood belief about misheard lyrics

others believed things like this
- I used to think the song "Walk this way" by Arosmith went horse and sleigh insted of singing walk this way.— Derek
- i was convinced that snow was pink, i was devastated the first i saw real snow.Anon
- a donkey is just a small horse.Anon
- I used to think that beer was horse pee. Probably because that's what my mom told me...— Kara
- When I was three I used to believe that cow and horse are wife and husband.— xenia
- I used to think giraffes were a type of horse— Crocotta1