An alternate and somewhat simplistic theory as to why we crossdress:
When growing up, we slowly discover the world and the things we enjoy. Some of us discover that we like things that are typically associated with the females of our species.
We only know this because we are taught what constitutes masculine and feminine behaviour, and what are considered masculine versus feminine objects, from a very early age. But, we beg to differ.
Imagine that strawberries would be reserved for females.
"F*ck that, I'm gonna have some strawberries right now!".
The point is, even though we know that we are being taught differently, we have a strong belief in our own choices, to the point that we will hide away from popular convention in order to do our own thing.
Yes, we can be a little secretive, and a sometimes a little unsure of ourselves, but we know what we like, and we have the temperament to pursue life as it feels best.