Excellent point! @irahul, I see that you view a library as the storage place for the books that one has read. It should come as a surprise that most researchers

Excellent point! @irahul, I see that you view a library as the storage place for the books that one has read. It should come as a surprise that most researchers/scholars view their private libraries not in this way, they view it as a source of information of mostly unread books. You should definitely read Eco's essay titled 'How to Justify a Private Library' in his collection How to Travel with a Salmon. In it, he discusses his answer to precisely the same question that you have put forth. Here's how he fantasizes answering the question "Oh, what a large number of books you have! Have you read them all?" "In the past I adopted a tone of contemptuous sarcasm. ’I haven’t read any of them; otherwise, why would I keep them here?’ But this is a dangerous answer because it invites the obvious follow-up: ’And where do you put them after you’ve read them?’ The best answer is the one always used by Roberto Leydi: ’And more, dear sir, many more,’ which freezes the adversary and plunges him into a state of awed admiration. But I find it merciless and angst-generating. Now I have falled back upon the riposte: ’No, these are the ones I have to read by the end of the month. I keep the others in my office,’ a reply that on the one hand suggests a sublime ergonomic strategy, and on the other hand leads the visitor to hasten the moment of his departure."