A 24-year-old boy, looking out from the train window, shouted:
"Dad, look, the trees are going behind!"
His dad smiled, but a young couple sitting nearby looked at the 24-year-old's childish behavoir with pity. Suddenly he exclaimed again:
"Dad, look, the clouds are running with us!"
The couple couldn't resist and said to the old man...
"Why don't you take your son to a good doctor?"
The old man smiled again and said:
"I did, we are just coming from the hospital. My son had been blind from birth, he has just got eyesight today".