You have to learn what Monad and Functor are, but you do not by any means need to learn what a monad is, or what a functor is. To put it another way, you need t

You have to learn what Monad and Functor are, but you do not by any means need to learn what a monad is, or what a functor is. To put it another way, you need to learn the Haskell type classes that have those names, but you do not need to learn the category theoretical constructs from which those names were taken. I believe this was the entire point of the article. The Haskell type classes are actually not too hard to learn at all, if you give it a bit of effort.