Subways are astonishing teaching machines. You learn a route: a number, an end station, and a stop, and you get an instant reward. The system is totally reliable and endlessly repetitive in structure. Every line works the same way. The attachments - busses and trains - work the same way, with small differences. One orients oneself to one system, then expands one's reach to an analogous system as one develops new needs and desires. 

Subways are also meta-teaching machines. They teach about teaching and learning, about what kind of structure should be there: repetitive patterns, systemic analogies, immediate response to obvious needs and desires. You expect of a theory what a good subway map shows, and you learn theories because you want something like a subway map for some part of life.

Here's another teaching machine, a slack line. You get on. You fall off. You see somebody walk across. You try again. You still fall off. You get the hang of it, eventually. From this, you generalise: confidence and trying until you get it right.

This is also a meta-teaching machine, with a much less definite message than the subway system.

So, a city, a culture, teaches you and also teaches you what learning means, and if it does that in enough ways, you are ready to learn the various things you need to learn.