Like many of the inventions on this list, the man we believe invented the printing press (Johann Gutenberg in the 1430s) actually improved on pre-existing technologies and made them useful and efficient enough to become popular. The world already had paper and block printing -- the Chinese had them as early as the 11th century -- but the complexity of their language limited popularity. Marco Polo brought the idea to Europe in 1295.
Gutenberg combined the idea of block printing with a screw press (used for olive oil and wine production). He also developed metal printing blocks that were far more durable and easier to make than the hand-carved wooden letters in use previously. Finally, his advances in ink and paper production helped revolutionize the whole process of mass printing.
The printing press allowed enormous quantities of information to be recorded and spread throughout the world. Books had previously been items only the extremely rich could afford, but mass production brought the price down tremendously. The printing press is probably responsible for many other inventions, but in a more subtle way than the wheel. The diffusion of knowledge it created gave billions of humans the education they needed to create their own inventions in the centuries since.