Looking back on life, I now see myself as always having been female. However, I only really recognized that I was trans sometime in highschool (iirc). While I have never identified as male or masculine, and have always thought of myself as feminine/girly, it was not until highschool that I became aware of the notion of transgenderism— aware of the possibility that I could be female and not just feminine.
Even after this realization struck, it took a few years to come to terms with the idea, and to realize that this possibility was indeed a fact about myself. This delay was for the most part due to the time it took to divest myself of the transphobic and homophobic parts of my upbringing. But eventually, removing that self-directed stigma, I recognized the truth. This was, literally, half a lifetime ago now. When I entered undergrad I sought to transition but, for reasons I'll discuss another time, decided against it. Still, I recognized that the only way I could be true to myself was to be open about being trans. So even though I decided against transitioning, I've been sure to let anyone who cares to know that I am trans.
After deciding not to transition lo those many years ago, it's a decision I'd never really revisited; much despite my dysphoria getting worse and worse. And then, for whatever reason, this past spring I was driven to reconsider. And, reconsidering, I decided to transition. I've been on hormones now for about half a year. In the beginning I noticed lots of little changes. The most important one was the sudden overwhelming sense of rightness. I've known unquestioningly I was trans for half my life now, and have been publicly open about that fact for well over a decade. But even though there's been no question in my mind for all that time, there's something fundamentally legitimizing about starting HRT and getting empirical evidence that, yes, my brain does in fact work much better on estrogen than testosterone.