Conformity with Clothing?

I have always found the clothing "trends" to be odd. Not the trends themselves, but the fact that one trend will resonate with a majority of the population for a given amount of time. It isn't probably that all of the people will somehow have a preference for the same type of clothing at the same time, and then switch together. I have always wondered, why is it that just five years ago, gaucho pants were "in," yet now they are considered "weird?" Why is it that ten years ago bell-bottom jeans were the way to dress, yet now its skinny jeans as the trend? When reading chapter 13, I began to wonder if it has to do with conformity. Do people really just wear what the want? Or are they conforming to a trend set by someone, or a small group of people? Are we all just conforming?