I came out a couple years back but, shit, I knew I was non-binary all my fucking life. In fact, you know what? As far as I can recall I have never, ever, stated this publicly before, in my thirty years on the internet, but I love Mastodon so here goes: I was born under different forenames, and by the time I was just eleven years of age (yes: eleven!) I knew I wanted them changed to forenames that were specifically non-binary, even though I was unable to articulate it in that way (I just said I wanted names that could be for any gender). But my mother supported me, and so my forenames were changed - and have been my legal forenames ever since. (Of course, a few who got close to me later enjoyed deadnaming me a few times over the years to score points.) A bit of further insight here: https://www.mediaactivist.com/im-coming-out-to-pyro-and-entrance-music/