I never believed that people could change sex, but was happy to respect someone's pronouns, etc, if they'd been so unhappy they'd required surgery. I always thought of them as a transwoman, or transman - something new and distinct from biological women and men.
I thought that the human body is so complicated, perhaps there's a hidden medical reason they feel the way they do - after all, people used to believe that being gay was a choice, rather than an innate trait. And to be honest, I still wonder this.
But I used to think that all transfolk would have reassignment surgery. The modern definition of trans, where you have transwomen prancing around in a very sexualised fashion and proud of their 'ladydicks' and calling lesbians 'genital fetishists' for not being interested, or transmen happily giving birth and demanding to be recorded as the father on the birth certificate - well, it's all a bit mental, isn't it?
As I got older, I also started asking questions like, "What makes me a woman?", and I couldn't answer that without resorting to biology. It's not my personality, or interests, or fashion choices (which are arguably more 'male' coded) - it's the female body I have.
Why is transgenderism accepted, but identifying as transracial isn't? There's less difference, biologically speaking, between a white person and a black person, than between a man and a woman. Both are biological states that inform how society interacts with them. I've never had anyone able to give me a good answer to that one.
How can a rapist who raped with his penis ever, ever be considered a woman? How can his victim ever be castigated for referring to him as male? Why are transwomen overrepresented in the sex and violent offender categories?
Honestly, I tie myself in knots about it because I know a fully transitioned transwoman, and she's lovely. If you didn't know, you wouldn't know. But she was also a very 'effeminate' boy as a child, who suffered from homophobic bullying, and I can't help but wonder if she would still be a he if boys were allowed to express what's traditionally regarded as feminine traits without castigation.