If you think, "I am doing a service", while you are serving, it is no good. Service should be part of your nature. When you do something for yourself, do you call it service? Do you say, "I'm serving myself?" No, because it's such a natural instinct. Any thing you do to your own children, do you call it service? You consider it your duty. So as a human being, our duty or our nature is to help others.