I knew I wanted to be a girl when I was 5. I remember the day quite vividly.
I'm not too sure how I knew I had to hide that desire very, very well; but somehow I did. While the thoughts & desires would resurface often over the years, I was always able to push them back down out of my conscious mind up until January of last year. That was when I realised that all the "fantasies" were not just idle dreams, but something real that was not about to go away.