If you ask anyone at a dinner party whether they’re a Scorpio or a Sagittarius, they’ll answer without hesitation. Newspapers provide daily horoscopes, and quirky short videos describe what fashion choices or travel destinations a certain sign should try. It’s such a noticeable part of our culture, but where did it come from?

Zodiac comes from ancient Babylonia, where priests and astronomers divided the sky into 12 equal parts, each 30 degrees wide. The names came from the constellations the Sun appeared to travel through over the course of a year. The Greeks refined the system with mythological figures and character profiles for each sign. For over two thousand years, this framework has shaped how human beings think about themselves and each other.

The Sun sign represents the general shape of someone’s personality and the “role” they play in daily life. To truly understand what’s going on inside someone’s heart, one must look toward the Moon sign. In astrology, the Moon sign is the side of you that you keep hidden. As astrologer Evangeline Adams put it, the Sun signifies your individuality, while the Moon signifies your personality. How can you find out your Moon sign?

To uncover your Moon sign, all you need is your exact date and year of birth. You can consult specific Moon Tables by your birth year and month to find the exact date the Moon transitioned into a new sign. However, many online sources also calculate that for free, so this can take only a few minutes. The benefits of learning about this outweigh all the efforts. When you discover the combination of your Sun and Moon signs, you gain a fuller image of your personality.

Two people can be very different even when they share the same Sun sign. For instance, Woody Allen and Bette Midler are both Sagittarians. Yet, these two are quite the opposite. Allen’s detached wit reflects his Moon in Aquarius, which manifests as emotional coolness and intellectual distance. Midler’s Moon in Cancer creates the energy of warmth and vulnerability, as well as deep emotional resonance. So, if you want to get a better understanding of your inner world, read more about your Moon sign.