A Clean, Well-Lighted Place

"How do you know it was nothing?"
People tend to overlook many things and many times they think when your rich you have no problems or worries. In this instance they miss the fact that besides his niece he has nobody in his life.
"You do not understand. This is a clean and pleasant cafe. It is well lighted. The light is very good and also, now, there are shadows of the leaves."
The older waiter realizes that the man although sad with his life, wishes to be clean and at peace. He sits in the shadows of the leaves but the bright lights make him feel better. This seems like a symbol for his life even though it is dark he prefers not to be dirty.
"the old man liked to sit late because he was deaf and now at night it was quiet and he felt the difference."
This shows the man prefers peace and is most likely frustrated he can't hear what is going on around him. Once the night comes its just him by himself with his thoughts.