Sex and gender are two different things, really: sex is about your biology/parts/genes/hormones, and gender is about how you identify/are treated by society. A lot of people don't make that distinction, though, and then you get into a hornet's nest of people who didn't make it past ninth grade biology telling a transgender person they couldn't possibly be what they say they are, because they're an innie in their pants! ...or whatever.
Oh man, when I took Spanish in school, for the first three years none of my teachers used nosotros, one of them specifically telling us she wouldn't because "they only use that conjugation in Spain" (what if we went to Spain?). Then in 10th grade, for one year, I had a teacher that taught it and expected us to know it, and then two more years of never using it. And honestly, I'm like, we're in Colorado, I say y'all, nosotros should be taught! LOL