"A monad is just a monoid in the category of endofunctors. What's the problem?"
Unless you took graduate math, the problem is the above could just as well be written in Chinese. Further complicating the issue is that once people do learn Chinese (or type theory,) they become unable to converse in any other languages — at best they mumble about burritos.
But the beauty and power of Monads stem from them being very simple concepts, even when you can't fully grok the type theory.
I'll try and show just that, explaining in five minutes what monads are, and why you should care.
No prior knowledge in category theory or Haskell expected.
Are you up to it?

MP3