Although clothing is functional, it can also be as a form of self - expression.
The fabric texture, the color and the design of the clothing all are expressions of the wearer. Have you ever noticed a person with a fiery personality that has an affinity for the color red? Or an individual who likes goth with an affinity for the color black? These are just a couple of examples. Clothing can also be used to help create an image: a business man in a gray suit, a seductive woman wearing a skirt with a slide slit or a hiker who wears clothes you might find in the "out back". A person who has a number of outfits may be fashion forward and may really enjoy their wardrobe. You referred to a wearing a different costume every day. Individuals who wear customs may do it for the fun of it or might find it a dramatic way to bring attention to themself. If you are really curious, you could always ask the person why they have such an expansive wardrobe. As a psychiatrist i could conjecture about this, but that person probably knows their own motives the best.