Yes, it is a gradual treatment. It's not as if a guy pops along to the doctor and says, I feel like a woman, and the doctor says, right, here are some hormone blockers, and we can book you in for surgery next month. It takes years, partly to monitor how serious the person is, and how it manifests itself. I think in fact, that many people never reach the stage of surgery, but are able to adapt in different ways.
It does raise many interesting questions about sex and gender, and if they are fixed biologically, or socially determined. However, that discussion tends to take about a jillion pages.
I forgot to say that there are also people who see themselves as genderqueer or genderfluid, and I doubt if they ever see a doctor, although they may see therapists and counsellors. (I used to work with Pink Therapy who deal with LGBT+ people).
