There's a chapter in Jared Diamond's Guns, Germs, and Steel that lays out how written language made its way across continents. Time again, individual humans demonstrated an ability to observe a set of symbols, reverse-engineer their meaning, and map it to something relevant for their own people. Language, miraculously, always finds a way. Take the Cherokee blacksmith, Sequoyah. He noticed settlers were using marks on paper to communicate, and without any prior knowledge, reinvented the concept of writing for his tribe. Within a few years, the Cherokee approached 100% literacy rate, exceeding their American-European counterparts.
This is the story of one person solving a problem on their own, and knowing exactly what his audience needed to adopt it. Sequoyah created something arguably better than the original because it was designed for Cherokee systems. He didn't have any context about European-American culture, didn't understand the language, yet was able to translate and transfer knowledge with ease and effectiveness. He knew writing's purpose (sharing information across time and space) and what his tribe needed (syllable-based symbols).