One of Hans Christian Anderson's most famous short stories is "The Emperors New Clothes." It concerns a vain Emperor who loves nothing more than wearing the finest of clothes. So he hires a couple of charlatans who convince him that they can make the most beautiful outfit made from an exclusive material that is invisible to all but the smartest and most noble. The Emperor's advisors can't see the material, but they pretend so as not to look stupid or unfit for their office. The Emperor also afraid of looking like an idiot also goes along with the charade.
Eventually the fraudsters finish the suit, "dress" the Emperor and let him parade around the kingdom. The townsfolk also play along with the pretense, not wanting to appear stupid. But there is a child in the crowd who blurts out that the Emperor is wearing nothing at all. Something that exposes the foolishness to everyone, who begin to laugh and mock. The Emperor also suspects the truth, yet continues his procession.
This is a deeply insightful story that exposes how we can know something yet refuse to acknowledge that we know it. We see this structure of "refusing to know what we know" beautifully expressed in the following advert from Thailand,