From what I've read, being transgender isn't about clothes and stuff at all, or not mainly anyway. It seems that people are born with a 'body map' in their brains that sometimes doesn't correspond with their actual body, so that they feel there are parts missing that should be there, and other parts that feel like they've been sewn on by Dr. Frankenstein. Of course people who feel like that would want to dress the way that in their culture corresponds with the sex they feel they really are.