TBD hit on it, almost exactly, while being a smart aleck. It's a way to tell someone, "Look, I know I have to (should) respect you, but I think you're a mindless boob with no imagination, so for once in your life pull your head out of your backside and listen to someone with some reason, would you please??"
It's used extensively in the military services, usually to tell an officer they're full of sh*t. :laugh: