I think it's because people commonly forget what it's like to be a beginner and which things that are obvious to them are not obvious to a beginner. This is pro

I think it's because people commonly forget what it's like to be a beginner and which things that are obvious to them are not obvious to a beginner. This is probably more true in Haskell where there is just so much that it's possible to learn that the most advanced Haskell programmers are very, very far ahead of the beginners.