Like so many of the above, I started early. Mom didn't explicity say she wished I was a girl, but she actually named me Kimberly. I was very attached to my older sister, and was regarded as a "house boy" whatever that entails, by my older brothers. I still can vividly recall secretly putting on one of my sister's slips when I was perhaps 4 years old.
I am absolutely certain that I am as I am because of some developmental conditions in the womb...and although I've managed to disquise some of the more feminine traits and behaviors when needed, they're always present. I'm just beginning to allow them to come out more these days.
