Sleight of Hand
In a typical magic trick, the magician holds out a deck of cards, asks you to take one, memorize it and replace it in the deck.  Memorization is easy.  After you give him back the card, the magician returns it to the deck, shuffles a few times,  and passes his hand mysteriously over the cards.  When he has your attention, he holds the cards in front of you and slides his hands up the sides of the deck.  Lo and behold, the card you chose seemingly floats up through the pack as the magician states, "Here is your card".

So, do you stand in awe, eyes bugging out, mouth gaping open, saliva dripping-- as he looks deeply into your eyes and says with complete sincerity and honesty, "I couldn't have done it without you".

Or do you simply and  politely, reply "Nicely done.  But I know how you did it!"

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