A spirit, an extension of one's self. Fashion talks, it can be an understated whisper, a high-energy scream or an all knowing wink and a smile. Most of all fashion is about being comfortable with yourself, translating self-esteem into a personal style. Fashion is a means of self-expression that allows people to try on many roles in life. It's a way of celebrating the diversity and variety of the world in which we live.
Fashion is about change which is necessary to keep life interesting.
It's also a mirror of sorts on society. It's a way of measuring a mood that can be useful in many aspects, culturally, socially even psychologically. At the same time, fashion shouldn't be taken too seriously or you lose the fun of it. The collections in Paris, New York and Milan, and now London, typically set the stage for the industry one year in advance. Though, I think the street is the real barometer of style.