Robert was trying to sell his house since long but couldn't succeed. One day, he took out a brick from the wall of his house. His wife angrily asked him, Why did you do that? Robert replied, You are foolish! You don't know anything. I know why am I failing again and again in selling my house. I have never shown its sample to anyone. Now I have got a customer. I have promised him to this brick as a sample of our house. His wife held her head at the foolishness of her husband.