Might also be a self-identity thing.
Like, for me the experience of being trans was basically more like the experience of always seeing myself as female, and yet it was society and my body chemistry that said otherwise.
Like, I don't feel "trans." The word "trans" as a root means "across," "beyond," "through." But to my own mind I really didn't ever "change," or even really "transition." Even now, I still feel a complete sense of continuity through my entire life, where I remember being my current self even back then, and it doesn't even occur to me that I was actually socially male while all of those things that I remember happened to me. I'll remember something from middle school, remember friends from back then, and then suddenly as I'm having that memory I'll realize "oh wow, I was actually a guy back then." Basically, it takes me conscious effort to realize it. That label is just something that happened to me, not something that I actually was.
And even though my body is different than it was, I don't even remember having that old body. Because even when I did have it, and did see it every single day, it wasn't me. The only person it was ever "me" to was society.
So although to society they may call me "trans," to me it doesn't feel like it. It's not so simple as having changed from one thing into the other, it's more like I was always female, and I always saw myself as my current female self, but nobody else could see it. So I really don't feel "trans" even though that is, in every way, the proper label for what I am.