Before learning Haskell, try learning lisp through SICP. Haskell is wonderful but it's mostly (not really but bear with me) syntactic sugar over lazy application, which is explained in SICP (as opposed to eager evaluation used almost everywhere else). Syntactic sugar makes the whole thing appear like dark magic but it's not. It's a few minimalistic rules applied over and over (at both language and meta levels).
I've been programming (dabbling, to be honest) in LISP since about 1980, I've never shipped any products in it. I wrote a couple of toy interpreters in college (after reading Allan's Anatomy of LISP) and some small projects, but nothing massive.
I read SICP when it first came out and did most of the exercises. Yet Scheme was a terrible language to ship software in (commercial implementations were basically toys). I assume that Common LISP was a lot better, but the real packages were expensive.
I guess the real problem is that I didn't have cow-orkers who understood my obsession with LISP, nor did I work on any projects that I could really use it for. Could have switched companies, I suppose, but I liked working on operating systems . . .
Aight, to each his own, a lot of Haskell mystery vanished when I saw it explained in terms of simpler languages (pattern matching, lazy evaluation, curryfication etc etc) but apparently that's not what's bothering you.
I think FP languages' reputation of being hard to learn is partly owed to intimidating terminology that makes certain concepts appear more difficult than they actually are.
