For instance, suppose there’s a glass here. You might know about a glass. But what if you need to design one? The moment a glass is proposed as an object to be designed, you start thinking about what kind of glass you want to design, and you lose a little bit of your understanding of “glass” Arrayed in order before you dozens glass vessels of gradually varying depths, from “glass” to “dish”. What if you are asked to clarify the exact boundary point between one and the other? Faced with the objects, you’re at loss. And again you become a little less sure of your knowledge of a glass. However, this doesn’t mean that your knowledge has been overturned. Indeed, it’s just the opposite. You’ve become more keenly conscious of glasses than before, when you understood them by simply unconsciously calling them all by the term “glass”. Now you actually understand glasses more realistically.
