Throughout human history we learned from the other people. The key to idea exchange lies in observation. While the Internet has improved the speed of communication it did nothing to improve the key aspect of learning - observation. This key human skill has been with us throughout. Let's say I notice that you have a better way to hunt deer - a task takes me days to finish, I will imitate your method. If I didn't imitate, I would perish [as you would hunt all the deer]. Thus, learning was often a survival requirement. In some sense, the people you see now are descendents of those who were open to imitation. Humans learned whenever they interacted with people other cultures.
Before the contemporary era, there were two main groups of people who helped spread ideas. These were the merchants and the religious missionaries. Both of these had a significant urging to travel long distances and learn distant cultures. For gold and heaven, they would risk everything they had and their risk taking was how ideas moved around.
Prior to the rise of the Internet, no innovation did more for the spread and democratization of knowledge than Johannes Gutenberg’s printing press. Developed around 1440 in Mainz, Germany, Gutenberg’s machine improved on already existing presses through the use of a mould that allowed for the rapid production of lead alloy type pieces. This assembly line method of copying books enabled a single printing press to create as many as 3,600 pages per day. By 1500 over 1,000 Gutenberg presses were operating in Europe, and by 1600 they had created over 200 million new books. The printing press not only made books affordable for the lower classes, but it helped spark the Age of Enlightenment and facilitated the spread of new and often controversial ideas.
Today we have internet forums. Back in Roman times they had real forums. These were big spaces in the middle of cities in which people gathered together and exchanged ideas with each other. Like many things in their culture, the Romans stole Forums from the Ancient Greeks. They had similar meeting place which they called Agora (the word Agoraphobia, fear of open spaces, comes from this word).
Prior to the internet, every town or village had some communal space where people gathered to share ideas, stories and frequently alcohol. These places haven't gone. We still have pubs and coffee shops and people are exchanging ideas in them at this very moment.