We do not have any way of knowing what inspired Gutenberg to come up with the idea of the printing press. He did not leave any diary entries telling about his idea. What we must remember, though, is that Gutenberg did not simply invent the idea of the printing press out of thin air. For the most part, he took ideas that were already in existence and aggregated them. The one thing that seems to have been his own invention was the movable type with letters on individual blocks. Like most inventions, the printing press was an aggregation of previously existing technologies. Also like most inventions, we have no record of when or why the inventor had the idea of putting the various technologies together in that particular way.