In past, people share their knowledge with their generations through telling stories, experiences. As in 100BC paper introduced in China. This invention changed things dramatically.
The first time paper invented in 100BC in China. The invention of paper created many opportunities to learn things more easily through reading. As things started improving, books become available and accessible to everyone.
In past, the holy books of religions were written on plants leaves. Paper change this trend altogether. As paper becomes cheaper and cheaper, more and more people have access to this invention.
The invention of the digital screen further improved book reading experience. Therefore, books become cheaper. And were easy to carry, read and consume on the go. Nowadays, a man can have thousands of books in a thumb drive and can read on any PC.