Haskell is such a distinct mix of features that make it great to use once you know them but somewhat difficult to learn from scratch.

One big fat clue that I wish I had been given when I was starting to try to figure it out on my own back in the 90's is that Haskell is kind of loaded up with syntactic sugar, beneath which is a relatively small core language that might be an easier point of entry into the language.

To be specific: infix operators, sections, multi-argument functions, partial application, 'where' clauses, multiple definitions of the same function with different patterns, implicit braces and semicolons inferred from layout, 'do' statements, if/then/else, [lists] -- all of these, and probably more, are great to use, but they all boil down to something like

  func = \arg -> let { ... } in case arg of { pat | guards -> f x y; ... }

and perhaps fully grokking these essential constructs before moving on to using them indirectly through all the layers of pretty syntax would have helped me understand all those features better.

ADDENDUM to forestall my inevitable hog-piling by pedants: yes, I know that 'let' isn't strictly essential, and I neglected to mention record fields, record updates, type classes, &c. Sorry. And I know that the Haskell standards have always defined higher-level constructs in terms of a core language. My point is that, at least for me, Haskell might have been easier had I been exposed to just that core language at first.

>and perhaps fully grokking these essential constructs before moving on to using them indirectly through all the layers of pretty syntax would have helped me understand all those features better.

This is the approach we take in our book, Haskell Programming from First Principles. (http://haskellbook.com/) The book starts with a _brief_ introduction to lambda calculus and builds on what the reader knows incrementally. You can see in our chapter listing: http://haskellbook.com/progress.html what order we do things in. Importantly, it's not just show & tell. The book has _a lot_ of exercises and detailed explanation for the concepts covered.

I'd worked with and taught quite a few people before starting the book, in addition to maintaining a fairly popular guide (https://github.com/bitemyapp/learnhaskell) for learning Haskell and helping people working through the recommended materials. Further, my coauthor on the book was completely new to programming when she began working with me. What we cover and in how much detail is influenced by working with her, our ~10 deep-dive reviewers, and the over 1,300 emails of feedback/questions we've gotten from readers.

What I did in the book is based on that experience and data. If I could've written less and still solved the same problems, I would've. Maybe a future edition will be shorter after we refactor some things.