It can vary person-to-person. I really came to understand when I was in middle school. I was constantly unhappy and I had no idea why. I realize now a lot of it was due to the fact that I was starting puberty. My body was releasing hormones, and when I started getting a figure, I didn't want to look at myself. In eighth grade, I tried to push myself into being kind of girly, but eventually came across this blog for transgender and nonbinary teens. It was the general idea of, 'If I don't feel like a girl, I don't have to call myself a girl.' That clicked pretty much immediately.