I used to believe that Cal Worthington and his 'dog' Spot were selling pussy-cows pussy-cows pussy-cows (go see Cal).
A childhood belief about adverts

others believed things like this
- I used to believe that kittens came from pussy willows.— hope
- I used to believe chocolate milk came from brown cows and regular milk came from black and white cowsAnon
- i used to think chocolate milk came from brown cows and normal milk came from white cows Anon
- When I was little I thought cows married horses, cows were all female and horses were all male. — Sheila
- I used to believe that brown cows made chocolate milk and white cows made regular milk.— andrew mient
- I used to believe that brown cows gave chocolate milk, and that white cows gave white milk.— James