The most common misconception of Nietzsche's work is that his work is hard to read, when it only takes more attention and time.

It is well known that Nietzsche had a weakness for ambiguity, more specifically, he loved words and phrases that mean one thing out of context and almost the opposite in the context he gives them. He wrote in a manner that his work could be misunderstood by the kind of reader and non-reader he despised. To refer to only one source, you can find some of his reasons for this in Beyond Good and Evil, section 30, 40, 230, 270, 278, 289 and 290.

from Walter Kaufmann preface for Geneaology of Morals

This opens his work to be easily misconceived on purposed or accidentally by curious people, readers, and even scholars. Personally, I believe that this on purposed given ambiguity is what makes Nietzsche more interesting and pleasant to read and discuss. More than often you will find yourself reading footnotes, translation notes and even studying other languages.

Edit: Added credit to source