That's an interesting insight - isn't the whole point of the indirection to free you from needing to understand the underlying data structure when extending thi

That's an interesting insight - isn't the whole point of the indirection to free you from needing to understand the underlying data structure when extending things? I feel the heart of the issue is surrounding a similar problem that message-passing set out to solve, perhaps encapsulation? You set up some boundaries to a thing and define some contracts for interacting with it, and in return you are free to separate the implementation of that from the consumer of that data. I worry that when people program in Clojure, they forget all the discipline that was embedded in some of the better parts of the previous language/paradigms they came from and mistake that as liberation.