I can tell a cat's gender just by looking at its face
I had a small talk with my friends who are also cat owners. I learned that they couldn't tell a cat's gender without looking at their genitalia while I could tell just by looking at their faces. There is something about cat's facial structure that helps me identify its gender to which I had a problem explaining to them. I thought everyone could simply do this which I thought it was strange. This discussion didn't apply to calico of course.