That's what I exactly tried to convey: I used that tactic when I was a beginner at Java and hadn't many problems with it. I used the same tactic when Generics came up. I hadn't any problems with it. The beginner can become a better programmer by reading the code. Now I am in a state where I can say: "this shouldn't be implemented that way". Which is completely different and grounds in being Java my native language.

I have casual encounters with Haskell since two years now. Library code is still hard to grok. Don't get me wrong: I like Haskell very much and I am pretty sure that its a decent language to write security critical code in, but I think this is still a problem for many beginners out there. I very rarely stumble on something and say: "hey, that's cool, I will use that in my code". But I admit that I give up after the third nested "lift-<whatever>" ;-).

I want the libraries help me understanding the language, not vice versa. But of course, that's not their primary goal.

When you were a beginner at Java, did you by chance already know how to program in an imperative or OO manner? I find it highly unlikely that anyone unfamiliar with imperative/OO programming in general would get any benefit from reading Java libraries. If you want to get benefit from reading Haskell libraries, just like in Java, you need to learn how to program in the paradigm. Not just "have casual encounters" with it, not just reading things about it, but actually learn the thing.

A direct analogy to what you're saying: When I was studying French, I was able to read articles above my level and get a decently good idea of what they said. Now I'm studying Chinese, and I can't tell at all what characters mean! This should not be surprising. French is very similar to English, where Chinese is very different. Of course picking things up in the latter will be more difficult. It would be absolutely absurd to blame the Chinese language for that.