" be on the lookout for chauffeur knowledge. Do not confuse the company spokesperson, the ringmaster, the newscaster, the schmoozer, the verbiage vendor or the cliché generator with those who possess true knowledge. How do you recognise the difference? There is a clear indicator: true experts recognise the limits of what they know and what they do not know. If they find themselves outside their circle of competence, they keep quiet or simply say, ‘I don’t know.’ This they utter unapologetically, even with a certain pride. From chauffeurs, we hear every line except this. See "

― Rolf Dobelli , The Art of Thinking Clearly