There are three phases of my life where the thought of wanting to be female arises, i.e. around 7, 25, and 43.
At 25, in 1992 that thought was not fruitful, as there was lack of external motivating factor and resources. At 43, in 2010, things were different, with the help of internet, I can reviewed the experiences of people who went through the process of transition, and resources on HRT has become available. These were the excellent, external motivating factor contributing to the fruition of that thought.
As for the term "becoming woman" is not very appropriate, as mentally speaking, there is no "becoming", only accepting the feminine aspect, instead of opposing it as we used to when in the male mode of being. In physical aspect, HRT helps in a limited way of transformation, added with makeup, feminine wear and accessories, are also due to our accepting these elements, to match our feminine mode of being.