I just made a memory connection that maybe explains some things:|
When I was a kid, until puberty really hit, strangers assumed I was a boy. Consistently. I at least once got sideways looks for wearing a dress consistently.
Maybe this is why despite my actual cisgenderness I am so angrily definite about accepting people's gender identity as they claim it.
I know how it feels when people wrongly assume your gender (and sometimes don't believe you when you correct them) and it's annoying, varying levels of insulting, and just really really tiresome to keep correcting them even when your family, friends, and birth certificate all back you up.