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.

Exercise may very well be the most effective instant happiness booster of all activities.

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

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.

Write down your barrier thoughts, and then consider ways to reinterpret the situation. In the process, ask yourself questions like... What else could this situation or experience mean? Can anything good come from it? Does it present any opportunities for me? What lessons can I learn and apply to the future? Did I develop any strengths as a result?

Happiness is not out there for us to find. The reason that it's not out there is that it's inside us.

Forgiving people are less likely to be hateful, depressed, hostile, anxious, angry, and neurotic.