I can't put a specific date on it. When I was a kid, one of the things my mom insisted on was buying me whatever the hell kind of toys I wanted. So (as I've probably said before on here) I had barbies wearing Transformers armor, and the Transformers lived in a big, pink mansion. I was all over the place as a kid, but I always, always wanted to be a knight. I saw "Dragonheart" as a kid, and I seriously wanted to be Bowen when I grew up.
While I was growing up, I wore jeans and t-shirts. I got forced into dresses on special occasions, and ended up getting them muddy/ripped/ruined. So, my mom stopped making me wear them. I catholic school, I wanted to off myself for being forced into jumpers and skirts, and rejoiced (as much as someone in a horrible school can) when I hit 6th grade and was allowed to wear pants.
I feel, honestly, that I've always been like this and just didn't know the word for it. I can't count how many times during high school, I'd tell people "I'm in the wrong body, I should've been a boy". People have always treated me more male, and when they didn't it's always offended me off and sickened me. I remember wanting to cut my chest off when I was 13. I never questioned my attraction to girls, but I always felt weird and called myself gay for liking guys.
I could list things off virtually forever. I just couldn't take it at the end if college. I couldn't keep lying, couldn't keep being someone I was.
I just remember this brief phase where I tried to force myself to be a girl, and I hated it. I felt disgusting, I felt like I had to tell everyone I met "This isn't me, this is a goddamn costume and a role that I hate".