This particular property of construction systems (such as programming languages) is both a powerful advantage and a diffi-culty. It is powerful because the complex-ity of an idea often inheres in the way it is represented, but that representation is not just in the program code.
I believe this is the same when it is applied to content knowledge. When we know what we are teaching our presentation of our lessons becomes more engaging. When the content knowledge is lacking, the lesson becomes less engaging. Students become disinterested and soon they don't come to class or they becomes disruptive in class.