It's significant that Charles' thoughts turn not to Emily, but to his father, and while he seemed to experience no emotion whatsoever about his engagement, here he is "hurt." What has hurt him is complex: it is a lack of power in himself, over himself, precisely as it relates to control of an idea (he can no longer think of his father in the old way). In this subtle passage Charles comes face-to-face for the first time with his helplessness before the power of the dream-ideal. This is the first tiny hint that his passion for the mine, which he thinks he controls, will come to control him.