Laura had taken up a part-time job to pay for her studies. She sold goods from door to door. One afternoon, Laura was feeling thirsty. She decided to ask for a glass of water when she reached the next house. When she rang the doorbell, a young lady opened the door. “Can I have a glass of water, please?” said Laura. The woman thought, ‘This child must be tired and thirsty. A glass of water will not do.’ So she brought her a large glass of milk. Laura thanked the woman and left. Many years later, Laura completed her studies. She was now a doctor. One day, a seriously ailing woman came to see Laura. It was the same woman who had given her a glass of milk many years ago! Laura cured the woman. When the woman asked for the bill, Laura wrote on it, “Paid with a glass of milk.”