Cherry is trying to explain to Ponyboy that their lives are not what everyone thinks them to be. She is letting him know that they also have pressures and stresses in their lives. She tells Ponyboy that the Socs are always chasing something, but they don't really know what they are chasing so they end up constantly buying, posing and trying to be what is "expected of them," but they end up still not knowing what it is they are chasing. The Socs lives turn out to be full of things, but not full. They have a lot of stuff, but no real substance.