[aufreak]

The pure functional world was pretty much impenetrable for me for that very reason ... until I encountered Monads in Haskell. Monads have changed the game completely by providing a very clean encapsulation of side effects in general. There are people who are trying to generalize it even further using what are called "arrows", but just groking Monads in Haskell will give you a new understanding, somewhat along the lines of what learning exterior calculus does to your view of traditional vector calculus.