Let's go back to our humble friend, the pencil. They're cheap. They're everywhere. But nobody knows how to make one. It is mentally and physically impossible. Think that through for a minute.
You would have to chop and cut the wood yourself. If you use an axe, you'd have to mine, smelt, and process the iron ore in the blade. And make the tools to do so. You'd have to find rubber trees to make the eraser -- hopefully you happen to live in a tropical climate. You'd have to extract and process the rubber yourself, and make all the tools for that yourself.
Then you'd need to mine and mold the aluminum for the little bit that holds the eraser to the shaft. And you'd need to know how to make yellow paint, and have access to all the ingredients. And how to make the paintbrush you need to apply it. Then there's the matter of finding graphite for the pencil lead...
You get the point -- even the everyday is way beyond the capacities of any individual. It takes thousands of specialists coming together from all around the world just to make a simple, cheap little thing you can buy at any convenience store for less than a dollar.
Insights like that are why I became an economist.