"You don't know diddy"

Posted by Dan Halyard on October 12, 2006

My father used the phrase "You don't know diddy" when I thought I knew more than he did. Last week in a meeting someone else used that same phrase "You don't know diddy". Does anyone know the origin and the meaning of the word "diddy"?

• "You don't know diddy" RRC 12/October/06