I think of cups two ways, the most common being as a symbol of close relationships; romance, dating, marriage, family, children, closest friends. The less common way is the more ancient association with the element of water and the idea of intuition.
This is part of the inspiration for my poetry collection, “Triquetra: The Dance of Worlds“. Relationships are a little like Venn diagrams. One circle overlaps the other, making a a new area, a shared ground that is the sum of the two parts…perhaps more. The two circle shapes don’t click together like jigsaw puzzle pieces, each completing the other. Relationships work much the same way. It isn’t about one person rigidly completing the other, but rather two whole, complete people whose lives touch, work together, and “Dance” together to create something new. The relationship is more than the sum of the parts. The relationship does not complete the people in it, it lifts them whole to a place higher than they could reach alone.
The same concept applies to more abstract relationships. Esoteric relationship with “higher self”, spirit guides, and the like is a real, valid expression of relationship. It is no surprise that the Ace of Cups is also associated with element of water, and with intuition.
As I see it, relationship is the crossroads concept of all the Aces. Just like Major Arcana had a functional meaning plus a a more subtle lesson in balance, the four aces have their generally accepted meanings, but also a more subtle, relationship driven archetypal meaning. The ace is about the essence of the relationship symbolized by the suite as a whole. There is even a hint of relationship among the aces themselves. The relationship with spirit/universe here echos the relationship with self/philosophy symbolized in wands. How we conduct close relationships can spill over into how we conduct ourselves in larger social and community relationships, as with the suite of swords. Of course, the most romantic relationships have a coins-like physical component as well.
If the ace of cups comes to you, then think about the essence of your relationships. Drink in the love you feel, and pour out love and gratitude in return. Like the bowl of a chalice, hold space in mind and heart for relationship and intuition to flow in. This kind of love, gratitude flows like water, and is just as essential.