Freedom!

That one word encapsulates my experience.
Much like others have said its just the ability to be myself. Just simple things.
I can talk with my hands without feeling judged. I naturally use hand motions a lot when talking. I have had to train myself over the years to keep my hands at my sides or in my pockets because yes I have had guys look at me funny when I talk with my hands.
I can let my emotions flow. It's tiring surpressing my feelings. Being the stoic man character is depressing. I actually feel happiness now.
Connected to the last two is letting my emotions be expressed in my speech. It really makes communication more fun. I can also get involved in conversations that have real meaning to me. For instance chatting with a few of the moms from my kids school about our kids. These kinds of interactions leave me feeling good.
Just feeling like I'm close to being what has been in my head my whole life. Not pretending, not needing to calculate if a particular movement will appear feminine to others, not hiding all the time, just living.

Jentay, I agree that there is no logic to it. After all logically why would someone put themselves through all the social upheaval? I've tried to explain the feeling of needing the change to happen and why it feels so important to be started as quickly as possible. I have found no logic just that I need it to happen. For me that's enough. For others, that's just going to have to do as I have no other answer.