For me there has to be more than just donning women's attire. A guy who dolls himself up for a Halloween party is not a cross dresser. A guy who wears women's panties is not a cross dresser. In my mind he has a fetish. In my mind there has to be some innate desire or need to emulate a woman. To appear as a woman. Personally, I do not like the term "hobby" being applied to a need to wear women's clothing. When I was going through inner conflict in the 1960's and 1970's I did not ascribe the term "hobby" to my desires. Although I have a preference for certain styles and looks (patterns, floral) those are choices as any natural woman will make to express themselves. I was not trying to "fool" myself by saying I was a male who had a "hobby" of wearing dresses. It is not the same as my stamp and coin collection or my collection of plastic model airplanes and helicopters.
I would have to add to your list:
...Is it when you realize there is a female component to your inner self connected to the need to emulate a woman?
