In our evolution, the human being has acquired information transmitting means of making complex sound from the mouth. It is an invention of words. The sound from the mouth disappears immediately. Therefore, we invented letters and books for long term stock of information. With this invention, human beings can accumulate knowledge beyond generations. However, the books were expensive because we make books by hand-writing.

In 1445, Johannes Gutenberg invented a method of mass replication, letterpress printing. The price of books fell, and many people became able to possess books.

After that, we invented copiers and the Internet. The cost of creating, duplicating, transporting and storing information has drastically decreased.

The decrease in those costs makes information easy to obtain — the amount of information available increases. As a result, we can get huge amounts of information every day, as never before experienced by human beings of the past.