For me personaly.. I have always sorta explored sexuality, been very flexible. I actually found out about my gender as soon as I was introduced to the concept, I was so busy with sexual orientation that I hadn't even thought of gender.
Looking back, a lot things make sense. Like I'd always use androgynous and feminine nicknames, always say I'm a girl although I did not identify as one, I've never been too much into feminine stuff, I still am not. I used to think I was gender queer, because I was a bit in denial about being transsexual, probably because transitioning fully would require having to go through a lot and having to explain why I've changed sex and such for so many people.