To know something utterly and completely, THAT NO ONE ELSE KNOWS. It is the most EXTREME form of self-righteousness, usually brought on by a chemical imbalance in the brain.
"There is no such thing as a chemical imbalance." Said Tom Cruise in response to a Matt Lauer interview question about Brooke Shields.
"Obviously unaware of his OWN cerebral chemical imbalance, Tom Cruise demonstrated what it means to be Cruisazy today, during his interview with Matt Lauer, stating there is no such thing. Apparently, only he knows things the rest of us do not. He HAS done the research."