As a youngster and under the misdirection of a manipulative older sibling, I believed dogs were all boys and cats were all girls. If a cat and dog had a family, the litter would be a mix of boy puppies and girl kittens. A couple of years later my sister shook my world by pointing out next door's dog was female!
A childhood belief about cats and dogs

others believed things like this
- When I was a little girl, I believed that all cats were girls and all dogs were boys. :)— Mary Ellen
- When I was little, I believed that all cats were girls and all dogs were boys. Go figure!— Laurie W.
- I used to believe all dogs were male and all cats were female. I still call dogs "boy" and cats "girl." — Kelly F.
- My sister and I thought cats and dogs were the same animal, the dogs were male and the cats were female.— Paul
- I use to believe that cats and dogs were the same species; cats were girls and dogs were boys.— poopcrystals
- I used to believe that all cats were girls and all dogs were boys.— jordan