I Don’t Know
What does ‘I Don’t Know’ really mean?
When someone really doesn’t know, the entire question asked of them sounds like fuzz. Their response is ‘HUH? WHA?’
When they say ‘I Don’t Know’ that is merely a piece of a sentence, the rest of which is: I don’t know where in my brain that data is stored so I don’t know where to retrieve your answer.
When you hear that response, rephrase your question. After all, the meaning of the communication is the response it elicits (an old NLP Truth), and you aren’t communicating well. So rephrase until you get a relevant response.
Remember that the Sender is responsible for the communication.