The phrase "complete misunderstanding" means that there has been a total lack of comprehension or agreement between two or more people. They have completely failed to understand each other's thoughts, ideas, or intentions. Full definition
That is a common but complete misunderstanding of what Jesus asked of us. (religion-online.org)
I find your complete misunderstanding of my posts somewhat disturbing. (nakedpastor.com)
This is the sort of thinking that has led to so much judgment, condemnation, and killing of other people throughout church history, and is a complete misunderstanding of the text. (redeeminggod.com)