It was the end of my exhausting first day as a waitress in a busy New York restaurant. My cap had gone awry（失败，出错）, my apron（围裙） was stained, my feet ached. The loaded trays I carried felt heavier and heavier. Weary and discouraged, I didn't seem able to do anything right. As I made out a complicated check for a family with several children who had changed their ice-cream order a dozen times, I was ready to quit.

Then the father smiled at me as he handed me tip. "Well done," he said. "You've looked after us really well."

Suddenly my tiredness vanished. I smiled back, and later, when the manager asked me how I'd liked my first day, I said, "Fine!" Those few words of praise had changed everything.