It just doesn't bode well with my way of thinking. I dunno what to put my finger on exactly but I just really don't enjoy coding in Haskell.
Mainly because it's a completely different way of thinking, instead in order statements, it's set of expressions and order does not matter unless you use monads. Your basically telling the complier what you want, rather than how to do it.
Also no side effects unless you use monads...
But the no side effects gives you really bug free code as they do not rely on external state which makes it very predictable , and the fact that the order of the expressions does not matter gives the complier the power preform optimizations on a bigger scale.
And the type system is one of the best things ever, as brief as a dynamic language(as most types are inferred) and as safe as a statically typed language.
Basically you need completely forget about imperative programming before you learn it. Start from scratch.
But a lot of modern imperative languages are putting functional features in now, so that may ease the learning process.
From purity point of view my most hated language php. It just reminds of badly designed perl(I like perl). The language libraries also switch naming conventions randomly to. The namespace controversies, the fact that they added goto when you've got exceptions, people were using php fine all the way up 5.3 and they never had goto.