This is one reason why I hate the "standard trans narrative" that EVERYONE was born this way, knew since birth, would rather die than not transition, etc.
I believe I sincerely was a cis guy, once, and was quite content being one. I wasn't born female; I was born a boy. I just... grew out of it? One day I realized that didn't fit anymore and hadn't for a while, and I changed my presentation [and eventually my body] to match. So I'm serious when I say I wanted to transition but wasn't sure if I was really trans. Yet here I am, happily living as a woman years later.
The thing is, since I've started telling this story, I've met other trans people like me, too. Not everyone knew since they were a teenager at the latest, and not everybody *can* fit into one simplified story, even if that's what cis people and the media prefer.
The strange thing is that there's this insistence about a lot of major life choices, when the truth is not every marriage lasts forever, not ever career is perfect forever, etc. *even when they were good and satisfying choices for a time.* The absolute worst case here is that you live joyously as a woman for some period of time and then decide even though it worked for you then, it doesn't now, and you change again until you're happy. It's OK. 🙂 That's what I've told myself, too, and while I still can't imagine NOT being thrilled by this new life, if that day comes in 15 or 20 or 50 years, it won't negate how I feel now or how right this decision was.