That turn on we experience when trying to emulate the looks of girls we find attractive is probably what started my crossdressing, a year or two before puberty. But "turn on" doesn't really capture the essence of the thing, which is (at least in my opinion) of a transcendental nature, a metamorphosis of some kind. Yes there is turn on. But it's more a byproduct than the core of it. Grown up women appeared to me like super beings when I was a child, and the effect they had on me a mystery I wanted to crack. Crossdressing was one of my attempts at solving it (there were others, such as drawing heroines in comics or writing erotic stories). Born from attraction, but fueled by the magic of almost touching their skies for a fleeting moment.