@Fieldofgreycorn
"There are 2 sexes. Sex is made up of more than just chromosomes or gametes. You can change aspects of your physical sex. Some people change their sex hormones, their secondary sex characteristics and to some extent their primary sex characteristics."
So what? They can never know what it is to be born and brought up and be the sex that they are not? If I were able to fuse a horn to my forehead and it were to somehow start growing I would still be 100% human (only with a horn); I would not be even 1% of the way to becoming a unicorn.
"As a society we treat these people - for most purposes - as if they have changed sex. Socially, legally and to some extent medically. (Where appropriate)."
I cannot believe that anyone is ever treated medically as anything other than their biological sex, subject to previously undertaken interventions, unless a mistake is being made.
That the law lies says nothing other than the law lies.
Socially I strongly suspect that most trans women are treated as men, trans women or people the vast majority of the time and are very rarely treated as women.
"Some people that do this resemble their transitioned sex more closely than others. Those that do have less problems being accepted as their transitioned sex in most situations. Those that don’t… well yes there is an element of politeness involved."
Yep. Similarly, fraudsters who closely resemble honest people have fewer problems conning innocent members of the public, whereas those who are blatant fraudsters are humoured but never get their hands on innocent people's money.