Dear Richard,
How we see the world may not necessary the same as what the real world is. Still remember the story of five blind people touching an elephant? Here I have another story to demonstrate this very common mistake.
In Jin (®Ê) dynasty (265 A.D. to 420 A.D.), there was a man called Le Guang (¼Ö¼s). One day, he invited one of his friends come home to have a drink. When they were drinking very happily, his friend suddenly didn't feel well and appeared to be very ill. His friend went back home and stayed on bed for weeks. Le Guang didn't understand what had happened. He asked his friend. His friend said, 'When I was drinking that day at your home, I saw a snake in my cup. Since then, I got sick.'
Le Guang went home and investigated. Finally, he discovered the reason. He invited his friend to his home again. He asked his friend to sit on the same place and gave him a cup of wine. His friend saw the snake in the cup again. When Le Guang showed his friend that the snake was actually a mirror image of a bow, which was hanging on the wall behind him, his friend laughed and his illness was immediately cured.
With love, Dad