When we are fully mindful of the transience of things - an impending return home from an overseas adventure, a graduation, our child boarding the school bus for the first day of kindergarten, a close colleague changing jobs, a move to a new city - we are more likely to appreciate [be grateful for] and savor the remaining time that we do have. Although bittersweet experiences also make us sad, it is this sadness that prompts us, instead of taking it for granted, to come to appreciate the positive aspects of our vacation, colleague, or hometown; it's 'now or never.'

...The more a person is inclined to gratitude, the less likely he or she is to be depressed, anxious, lonely, envious, or neurotic.

The combination of rumination and negative mood is toxic. Research shows that people who ruminate while sad or distraught are likely to feel besieged, powerless, self-critical, pessimistic, and generally negatively biased.

If we observe genuinely happy people, we shall find that they do not just sit around being contented. They make things happen. They pursue new understandings, seek new achievements, and control their thoughts and feelings. In sum, our intentional, effortful activities have a powerful effect on how happy we are, over and above the effects of our set points and the circumstances in which we find themselves. If an unhappy person wants to experience interest, enthusiasm, contentment, peace, and joy, he or she can make it happen by learning the habits of a happy person.

I prefer to think of the creation or construction of happiness, because research shows that it's in our power to fashion it for ourselves.

Thus the key to happiness lies not in changing our genetic makeup (which is impossible) and not in changing our circumstances (i.e., seeking wealth or attractiveness or better colleagues, which is usually impractical), but in our daily intentional activities.

All that is required to become an optimist is to have the goal and to practice it. The more you rehearse optimistic thoughts, the more 'natural' and 'ingrained' they will become. With time they will be part of you, and you will have made yourself into an altogether different person.