Like so many others, I, too, beliived for a long while that all cats were girls and all dogs were boys. My best friend's little brother, though, knew better. HE was positive that boy dogs had boy puppies, and girl dogs had girl puppies.
A childhood belief about cats and dogs

you weren't the only one
215 of you believed this
- I used to believe that cats were all female and dogs were all male.— Rachel
- that cats were only girls and dogs were only boys. I definetly didn't get the whole reproducing thing yet.— Jamie
- i used to believe a dog was the male version of a cat.Anon
- I believed that all cats were female and all dogs were male. — Biologically confused
- i thought cats were girls and dogs were boys. Anon
- i used to believe that all cats were female and dogs were male!Anon