Read this: http://learnyouahaskell.com/chapters
Just don't skip chapters and read from the beginning to the end.
Just don't skip chapters and read from the beginning to the end.
Similarly, you may know what eigenvector, or derivative function, is, but without practice you can't understand why you may want it.
I have similar issues elsewhere when people start with hello worlds and getting started in introductions to projects and programming languages without spending enough time on what the thing is about.
Why can't you learn chinese very fast if you already know a handful of european languages ? The answer is the same : the underlying concepts are different.
Sadly, there is no easy shortcut to understand these concepts. The best that can be done (and it's hard enough already), is to make learning entertaining.
I think half of people failing to understand monads are people failing to understand typeclasses or HKT while trying to learn about monads. Once you get those, all you need is the Monad typeclass definition and a huge pile of motivating examples.
The Z is Y. The Y is an X that does W. ...omitted... Here's C, B and A. Now you understand!
First comment in this thread is exactly like that. Definitions, not explanations.
And then after telling you how monads are different than map for things that are _not_ lists, a bunch of follow up comments talk about... Lists.
Pedagogy does not work like that. What is it about haskell that ruins people's ability to explain things?
I'm not saying you shouldn't use examples to learn, I'm saying you should probably learn X and Y (type classes and HKT) before you try to learn Z (monads). Use as many examples as you like to learn them, but if you don't understand type classes and HKT, you will probably struggle to understand monads.
Haskell is the most maddening language to learn purely because of the community around it.