Costumery, fancy dress, getting dolled up in things not normal to us, is as much a part of the Attire language as your blue jeans, or your favorite shoes. Being in costume, choosing to step outside your daily routine, is a massively freeing experience. It allows us to express hidden feelings and thoughts with impunity; because a costume party, or other costumed event like Mardi Gras, Carnivale, or Halloween enables us to do so without fear of disapproval. For some reason, we allow ourselves as a community to look on people with much greater indulgence and acceptance. Many is the time that I have seen tourists cozying up to outrageous drag queens, to be photographed together, while in real life they might not be willing to acknowledge them.
Costume is a zone where no matter what your thought process, or feelings, you can safely express them. So I say bravo and three cheers for costume. Its the opportunity for the most buttoned up of us to cut loose, and the most loosely defined of us to zip it shut for a while.