Well, thinking back, I've gone by a bunch of different labels until I realized I was trans, so it was always "I want to be a man" because I thought, you know, girls had vaginas, and since I had one, that meant I was a girl.
Honestly, I went from depressed bisexual female, to depressed tomboy lesbian that didn't feel that she was a lesbian, to depressed bisexual female again, to bisexual uncomfortable genderqueer (fff, I was two people in one perhaps? A boy and a girl? SURE! I still had to be a girl, right?), to confused questioning transman, to genderqueer again because I decided that I was too feminine to be a boy, and then finally back to being a transguy. And that's the way it's going to stay because I'm quite happy as a boy.
Anyway, I have yet to medically transition, but it was always "I want to be a man" because I thought, "I want to be a boy, but I'm a girl, so I can't be, right? Besides, I'm not that masculine."