Humanity has been working hard on learning how the world works. One crucial aspect of this effort is to educate the next generation in everything that has been learned through long studies and arduous experiments. To achieve this goal of educating the next generation, we store the newly acquired information in books, archives, videos, voice recordings, etc. In some cases, we even utilize presentations and educational videos that are specifically designed to teach the subject as quickly and as efficiently as possible. These types of presentations are obviously more common for entry level learners than academicians and other advanced learners. Nevertheless, we are doing our best to make the learning experience as easy and as smooth as possible for anyone who is interested in learning.
This incredible focus on learning and teaching is not only because this is related to economic forces, but also we have no other choice. When something is written down in a book and as long as that book is not burned, we tend to assume that this information is secured in the memory of humanity. For now, this is basically correct since most people have sufficient time to learn as much as they want on a certain subject. However, the amount of information necessary to become an expert on a subject is increasing constantly. To conduct cutting edge research, it is commonly assumed that one first has to learn everything that is already known in the field. At some point, it will become almost impossible to learn everything on a certain subject so that new research can be conducted to further the knowledge of humanity.
As long as the learning rate and life span of humans stay finite, we will hit a wall of knowledge where learning more will be impossible. The amount of information one person can learn is a compounding of the rate of learning and the duration of learning. Since both of these factors are finite, we cannot indefinitely increase how much we can learn. No matter how much information is written or recorded if a human being did not read it, it cannot be considered part of human knowledge.