In the 5th century BCE, the Temple of Apollo in Delphi, a province of Greece, bore this inscription: “Know thyself.” Twenty-five centuries later, it remains important advice. In his leadership classic, On Becoming a Leader, Warren Bennis stated that knowing oneself “is still the most difficult task any of us faces.” I agree. We inhabit many roles in our lives; we present different faces. How do we truly know ourselves?

Psychology provides many tools to help us, including, as needed, a variety of therapies. As a cadet at the USAF Academy, my classmates and I were required to have a talk session with a psychologist so that, as future leaders, we would understand the help and benefit psychologists can provide. For insights into one’s personality, the Big Five Personality Theory is excellent. Jennifer Fayard’s recent Psychology Today blog is a good place to start; it also includes a link to a Big Five test.

We have different attitudes and emotions. Do you know your aptitudes? What are your strengths? Your weaknesses? We are shaped by genetics and experiences. There is always more to learn.

The more insight we have into ourselves and our behaviors, the higher the probability of expanding our potential and of having a “good life.” For years, psychologists thought about a good life in terms of either “happiness” or “meaning” or both. For some people, a happy life is a good life. Many things affect happiness. At lower incomes, money is a larger factor. As income increases, the relationship between money and happiness decreases. Healthy relationships and interactions with others are also key. Being grateful and showing appreciation are behaviors related to happiness.

While happiness and “the pursuit of happiness” are important, for some they may be insufficient. What is the nature of “meaning” in how you see your life? Oishi and Westgate found three common characteristics in definitions of meaning used in research about meaningful lives:

• “the subjective sense that one’s life matters”
• “the extent to which life roles and experiences fit together into a coherent whole”
• “the perception that one’s life has direction and contributes to something greater than the self”

If you perceive these characteristics as important to you, then “meaning” may be an important dimension in how you enact your life. For some, a purposive life is a good life.

Happiness and meaning are two dimensions by which one may define a good life. Oishi and Westgate added a third: “psychological richness.” They suggested that happiness and meaning do not fully capture behaviors and experiences that some may associate with a good life. These are indicative of curiosity, spontaneity, various interesting experiences, and experiences that change one’s perspective.

These three approaches to life do not compete with one another. One is not better than another. You may fit one, two, or even all three. But understanding your approach to life can help to know yourself. How would you characterize how you live your life? How do you want to live your life: Happy? Meaningful? Psychologically rich? Or a combination of two or three? Time and situations affect how we move through life. There can be times of greater happiness, feelings of greater meaning, and experiences that are psychological rich.

As a young man browsing in a bookstore at Wake Forest University in North Carolina, I came across The Thoughts of Henry David Thoreau, a book I still cherish. These words resonated with my teenage mind and became my motto for this life: “If I am not I, who will be?” Grow in knowing yourself.