Start by listing down five things you are grateful for and do that once a week. It could be the people who are or were in your life; the possessions that have meaning for you; the generosity of a stranger or a skill you have picked up and the sight of a sunrise that left you awestruck. Just writing a sentence about each of the five things once a week for two months can make you more optimistic and happier. Gratitude is different from indebtedness. Indebtedness creates a feeling of obligation to pay back. Gratitude makes you realize that you matter much more to the person than you ever imagined.