No act of kindness is ever wasted :

One day, a poor boy who was selling goods from door to door to pay his way through school, found he had only one thin dime left, and he was hungry. He decided he would ask for a meal at the next house. However, he lost his nerve when a lovely young woman opened the door.

Instead of a meal he asked for a drink of water. She thought he looked hungry so brought him a large glass of milk.
He drank it slowly, and then asked, "How much do I owe you?"
"You don't owe me anything," she replied. "Mother has taught us never to accept pay for a kindness."
He said, "Then I thank you from my heart."

As Howard Kelly left that house, he not only felt stronger physically, but his faith in God and man was strong also. He had been ready to give up and quit.
Year's later that young woman became critically ill. The local doctors were baffled. They finally sent her to the big city, where they called in specialists to study her rare disease.