Most cartographers neglect map legends. They put a lot of efforts in the projection and scale choice, data and pretty colors selection, but then they just want to add a powerful title and press the share button. That is a mistake, as the cartographical legend is the key to understand the map. It is like building a beautiful door and forgetting to put a keyhole on it. It sounds obvious to say, but it is a major communication issue found in very prestigious media maps, still today. When maps were made by hand, making the legend was part of a very artistic process. This article puts side by side recent maps made with computers and ancient ones, drawn by hand, on purpose, to illustrate better the importance of skills and knowledge over technology when it comes to mapping.