Even if you never acted on your compulsion till much later.
Just a theory that might pertain to some folks here.
How many of you were born male but had sisters of any age? This also applies to all those that started much later. Even if you remember a very happy childhood with "oodles" of attention, isn't it likely that the girls got more attention and more praise at least as far as APPEARANCE goes?
There are some here who seem somewhat "ashamed" or really don't know why they feel the need to crossdress. Isn't this just ONE possible cause? Or contributing factor?
And if you had sisters, isn't it a good possibility that the stuff you tried on first belonged to them? And it simply felt good. Of course too, at a young age, there is always the "thrill" of getting away with anything. Might be especially true with a sister's clothing?