Why is language change so important? Quite simply, because language isn't just about communicating — language is also about how we think of things. Our concepts are bound up in language, and as new terms and new uses arise, so do our ways of understanding. When we learn a new word and make it ours, we do more than just add it to our store of terms. We understand the world differently, either a tiny little bit or, in the case of some words, dramatically. The first time we heard the word "astronaut," our entire world-view was affected. The same is true, in a different way, of the first time we understood what "downsizing" meant.
—Neil Randall, Canadian author and academic, Lingo Online: The Language of the Keyboard Generation, 2002