Zen, knowing ignorance & Janis

Perhaps we should reflect more about the nature of ignorance in order to understand more about the true nature of knowing.
 
Sharon Janis in her excellent Spirituality For Dummies suggests that;
 
 
There are two kinds of ignorance: positive ignorance and negative ignorance:
* Positive ignorance is when you don’t know and you know you don’t know. This awareness [...]