I'll agree that the terminology is not helpful to most people. But I would contend that if you understand object frameworks with callbacks, you already underst

I'll agree that the terminology is not helpful to most people. But I would contend that if you understand object frameworks with callbacks, you already understand a useful and practical way of seeing functors and monads without being aware of the fact. And if you understand the basic idea of git, you already understand the idea of building new data structures that share large immutable parts of old structures.