@augustus 
Probably very simple understanding of this cos pssh I'm hardly an expert.

But far as I know, gender is mental, sex is physical.

So like...I'm a woman, was born one, and I don't really think too much about it but I just sort of -know- I am one.

For some others, they were born, or are, in sex, whatever. But they just sort of -know- that they're...not that. Then that disconnect messes with them.

In terms of trans people, I don't think they -require- other people to think they're whatever they present as, cos it's more about having the right sex, than...gender. So when they get a sex change, they're closer to the body they want, so that's better. 

Like a born a dude, might sex change to have a lady body, but still wear dude clothes. Cos 'dude clothes' is the gender bit of it. Lady body is the sex bit of it.

I think.

Could be wrong, that's just my understanding. Trans activist types on Masto n stuff, don't tend to help matters.