Knowing what gives your life meaning and what gives you a sense of purpose is the path to finding your happiness. In a University of Wisconsin-Madison study, researchers found that people with high scores for having a sense of purpose in life also enjoy a strong sense of happiness and satisfaction. The people who ranked high in this characteristic, one of six measured by the Ryff Scales of Psychological Well-Being, had a sense of direction and were aware of the meaning of their lives. More from Prevention: 10 Secrets Of Happy Women Knowing your purpose may also help you live longer. Explorer and author Dan Buettner led a global study of populations who live the longest (in areas of the world he calls blue zones). Buettner found that having what the Okinawans call ikigai and the Nicoyans of Costa Rica call plan de vida—which translates as “why I wake up in the morning”—is worth up to 7 extra years of life expectancy. (Not convinced? Meet three far-flung local women who boast people with levels of energy, immunity, and happiness few of us know.) How do you find or rediscover yours? Over time, your purpose can change or even get lost. Try this: Think back to a period of your life when you felt satisfied and fulfilled. What were you doing? Whom were you with? Ask yourself what and who matter to you most. Philosopher Lao-tzu says, “At the center of your being you have the answer: You know who you are and you know what you want.” The answers will program your personal GPS. The next step you take—with intent and purpose—will be on the true path to lasting happiness. More from Prevention: The Happiness Trick You Haven’t Tried