Say it fast, it sounds funny.
Broken down this is a quintessentially Jersey response to someone asking “What do you mean?” (phonetically – Whadayamean?). It is the natural reply someone would give when they don’t quite understand what is being told to them.
To which you, or the person being queried responds, in exasperation, ‘Whaddayamean, ‘whaddaymean?’?!
Because you (or the person doing the explaining) can’t, at that moment, understand why there is a lack understanding on the receiving end (neccessitating yet another explaination).
It is a result of not understanding why the other person doesn’t understand or why they are asking (perhaps in exasperation themselves) ‘whaddaymean?’ Because you, yourself, don’t understand their lack of understanding.
It’s all very clear.
(follow the punctuation, folks. It is very telling).
Person1: Then, if you see the light on the VPN connector is still lit and connected, disconnect it.
Person1: Whaddaymean, ‘whaddayamean?’?! If the connector is connected, disconnect it. Simple as that.
Person2: Oh. Got it.