阅读短文，回答问题。
An old man walked slowly with a cane (手杖) into the restaurant. His old jacket, worn-out （穿破的）shoes made him stand out from the usual crowd.
A young waitress watched him move towards a table by the window. She ran over to him, and said, “Here, sir…let me help you with nodded (点头) to show his thanks. After he finished his breakfast, the waitress brought him the change (零钱)from his bill. She helped him up and walked with him to the front door.
When she went to clean his table, she found a note on a napkin. Under the napkin was a 100-dollar bill. The note on the napkin said, “Dear miss, I respect you very much and I can see you respect yourself, too. It shows by the way you treat others. You have found the secret of happiness. That is your kindness. It will make everyone you meet happy.”
The old man she served was the owner of the restaurant.
What was the old man wearing when he walked into the restaurant?.
What did the waitress find when she went to clean the old man’s table?
Was the old man the owner of the restaurant?
According to the passage, what is the secret of happiness?
What can you learn from the story?