Dysphoria that I accurately recognized as dysphoria? Around 2018-2019, in my late 20s. Prior to that, if you had asked me if I was trans I would have emphatically denied it, and frankly I would have meant it. That said, I think I have always been trans/nonbinary but I didn't label it as such.
Until the last half-decade I only knew about binary trans people and I figured that if I were that kind of person, I would know. I was not uncomfortable with my body, and in fact I thought I was a fairly attractive cisgender man. I accepted the default that society gave me, because I didn't really realize that there was any other way to be. However, I envied women and I longed for femininity. It was difficult for me to separate attraction from these feelings, but the first time I heard a gay woman say "I don't know if I want her, or if I want to be her" all of these confusing thoughts crystalized in an instant. That left me in a weird spot because the narrative I had for transness was only "born in the wrong body", which didn't really fit me. However I also knew that I felt trapped and frustrated by masculinity. When i finally learned that nonbinary, demiwoman, and genderfluid identities existed, it clicked.
Now I look back with the benefit of hindsight and can identify a whole lot of eggy thoughts and actions in my childhood. Now it's obvious.
I feel a little embarrassed by my path, because to an outside observer it sounds a hell of a lot like "rapid onset trans mindvirus" bullshit that the fascists like to rave about. However, that's not really an accurate description of what happened. It was closer to driving around your whole life wondering why your brakes squeal when you use them, and then having someone tell you about the little bumps on the backer of the brake pads that make that noise when they wear down, and that you should probably replace those pads ASAP. In hindsight it's obvious and you wonder how you made it so far without knowing something so basic. It wasn't indoctrination, it was education. I know I don't have to tell everyone here that, but I end up having to explain this so much to everyone in my life that I get a little defensive about it...