"Can you tell me how much that book on the table is?" "I'm sorry, I'm not sure which one you mean, what's the title of it?" "I don't know! Shouldn't you know that? Are you new?" "I'm not sure which specific book you're referring to. If you want to grab it I can check the price for you." "I'll just go ask somebody who actually knows how to do their job!" I work in a BOOKSTORE. There are a LOT of books on tables. I don't just magically know which book out of THOUSANDS you are referring to.