A fall into the pit, a gain in your wit

Uncle Zhang San is a kind man, he always helps poor people. One day, a girl came to his house and cried, she told Uncle Zhang San her parents dead in a fire accident, and her house burned, she have anything, but she doesn't want depend on other people, she want do business by herself, so she wanted lend money from him. Uncle Zhang san agreed her request and lent her some money. The girl wrote a receipt for a loan. She wrote her address and phone number, she said she will pay off her debts after two month.
After two month, nobody come to Uncle Zhang's house return his money, he think may be she still no money, I just wait. ....................After one year, still nobody. He try to find the address that girl wrote to him, however it's wrong address. The girl defraud his money.
Uncle Zhang San said to himself :"A fall into the pit, a gain in your wit."