Oh my god yes, It changes everything allows us to grow into ourselves. Or at least thats what my expierance has been. One of the biggest moments i remember that really caught me off guard was hanging with one of my guy friends and storming away saying Men or such ->-bleeped-<-s. That's only one instance there have been so many more like going from green to pink as my favorite color. Don't get me wrong still love green but theres some irony in the fact that Pink is literally the absence of green and that it was like out of no where that i would choose pink before green. I think estrogen effects us at that level because for trans people going through the puberty of the opposite gender that we are just leaves us paused at that state, never growing and developing completely into ourselves. Hormones play a huge role in the development of boy's into men and girls into women and for those who are trans the incorrect hormones leave us hanging in the balance. So when we do seek transition with the correct hormones we finally grow into the women/men we were meant to be. For me, the parallels with female puberty were so apparent, I noticed i even started acting like a teenager again for a time. My ambitions changed, my passions changed, I started looking at men in a light i didn't expect even being bisexual already there was something different. I reacted differently to situations became upset when my friends would well be guys and talk about girls the way guys do. It is different for everyone though, I think we all vary so greatly in the amount we repressed verse the amount we embraced. I myself repressed a lot and for that i noticed a lot but there were things i knew that were simply just surfacing because i was finally accepting of who i am, and then there was a lot of things that were completely new both in thought and action I believe was the effect of brain chemistry changing. Some things very "girly" and some things quite to the contrary but non the less cherished. I apologize for the grammar been drinking a little =)