As a girl growing up, I always knew that I was attracted to girls. I just had no reason to believe that I was different than anyone else in that respect.
I was raised in a fairly conservative Christian community, and the spectrum of sexualities and genders that a human being could possibly engender were not made available to me as options. I had no language to name how I was feeling. Because I had been assumed to be cis and heterosexual, I assumed that the way I felt in my body and in relation to other people was how everyone else felt.
Coming out was not about finally realizing who I was; it was about realizing that there were other people that did not feel the way that I did, that there was language to name how I felt, and that I was not alone.