ruled by the Moon
Cancer is by far the most sensitive sign of the zodiac. People born under this sign are touchy, easily hurt and they tend to withdraw quickly. The world of emotion is their kingdom. Their home is their palace. In it, they can care for their loved ones and provide them with unconditional support and self-sacrifice. Cancerians' top priority is emotional (and material) security. They instinctively know how others feel and what they need and they provide it to them with the readiness and pleasure with which a mother nurses her newborn.
People born under this sun sign have an unmistakable girl/boy next door kind of feel about them. When you look at them, there is something warm and caring about their faces that screams "you can go and cry in their arms and it won't be awkward".
Wherever they go they bring with them the vibe of a caring family. It matters to them that everyone would have their emotional needs met and would feel safe to express their true emotions at any time. The reason why this is uppermost in their minds is because they have very often been surrounded by people without this sensitivity and they know how hurtful it can be to not be emotionally supported.
When they are on the receiving end of such experience, Cancer people withdraw from the world into their shell and it takes a lot to get them out of there. They are very sensitive - this is how they are able to know how everyone feels at all times. But at the same time, this sensitivity is what makes them vulnerable to rude and inconsiderate behavior. They easily get in touch with the moods of others, hence their reputation for being moody themselves. Remember that they are ruled by the Moon, the planetary body that moves faster than any other.
Because of their innate readiness to respond to the needs of weak, vulnerable and marginalized people, Cancer people often end up being used and then abandoned. When that happens they are like a child left behind by its parents - there is an overwhelming sense that the world is cold and unjust.
Cancerians are passionate about ancestry, history and roots. Family is everything to them and they seek to create a family wherever they go. They color their interactions with a gentle, loving and soothing hues that create a feeling of hospitability for everyone around. They avoid raw behavior and conflict almost as much as Libras. Because of their attachment to all things past, they can have a hard time letting go and will often cling to past hurts and dissolved relationships long after everyone has moved on.
In romantic relationships, Cancer people look for people who value family and roots. They want to build a relationship within which they and their partner can be tender and vulnerable without reservations. When they talk to people, they focus on feeling this person out rather than on the information that has been exchanged. They want someone receptive of their magic, their magic being making people feel protected and understood.
Cancer people teach the rest of the zodiac the importance of having a supportive home environment and how foundational that is for a mentally healthy individual and someone's overall life.