That might be a strong argument in many languages, but in Haskell you really don't need to memorize operator precedence. In nearly every case, the types tell you the precedence. They don't literally, but most expressions only type check in one particular parse tree.
As a result, you just don't think about precedence when reading code. If you assume the code type checked correctly, you know that it all just makes sense. You don't need to create a parse tree. You just trust.
(Actually, this is the huge advantage of Haskell in most every case. You don't need to understand everything. You just trust that it does what makes sense, and you're right. The compiler enforces it.)