I used to believe that cats were female and dogs were male. They would get married and have babies together and the little boys would be dogs and the girls would be cats. I believed that until I was about 8.
A childhood belief about cats and dogs

others believed things like this
- My sister and I thought cats and dogs were the same animal, the dogs were male and the cats were female.— Paul
- I used to believe all dogs were male and all cats were female. I still call dogs "boy" and cats "girl." — Kelly F.
- I use to believe that cats and dogs were the same species; cats were girls and dogs were boys.— poopcrystals
- I believed that all cats were female and all dogs were male. — Biologically confused
- I used to believe all cats were female and all dogs were male.— Sabby
- I used to think that all cats were female and all dogs were male. — Annalisa