And when I said pen I meant fountain pen. It’s counterintuitive but probably more people today can draw a conceptual diagram of a ballpoint than a fountain pen. Ballpoints are a very simple design limited only by the very tight tolerances need to make them work.
But that was my whole point, complexity got so high that most things around us cannot be built without specialized tools, specialized building blocks, and specialized knowledge that takes years to gather. And this needs to be repeated for almost every object. Different tools, building blocks, and knowledge.
A highschooler today knows more chemistry than Mendeleev but that doesn’t help because the complexity in each field or product increases faster than one person’s ability to keep up with learning.