Everyone feel gender differently, and transness is just as much of a spectrum as gender. For me transness was realising I'm really just not into gender (I have more of a chaotic/impending vibe than a specific gender), for my friend it was realising he actually did want to be recognised as a man. For some it's wanting to explore lots of genders, or disliking the idea of being gendered entirely.

Honestly I think there's a huge portion of the world who are only gendered because of cultural hegemony, and would be nonbinary without social pressure because they just wouldn't care enough to perform.