Knight of cups: sufficiency, waiting, success in stillness.
Cups is associated with the element of water, and has close links with intuition.
I think this intuitive symbolism stems from the idea of receptivity. You don't get intuitive insight by going out after it, clubbing it over the head and dragging it home like a caveman's favorite meal.
Intuitive insight more often comes like ripe fruit falling from a tree. Or waiting for the ripening of a harvest...like one food company recently advertised..."only the vegetables know when they are ripe"...or something like that.
You wouldn't expect that sort of approach from a knight card. Knights are powerful go-getters, cards of action. In this case the ACTION needed is a combination of some of the other card ideas that have come up recently...waiting, watching, learning, and now attracting.
Attraction can be a powerful thing...look at nature, and all the colors, pheromones, musks and dances that go in to mating. They are doing something...like a knight would...but the thing they are doing is yin, not yang, attracting rather than seeking, magnetic rather than electric.
The difference between passive nothing and powerful attracting is mindfulness. It is intent...the intent that you choose and set. It is watching instead of sleeping.
The images and characters in literature, even popular media that combine yin and yang in this exquisite balance are very powerful ones. Sorcerers and wizards are an example....the women warriors of China like Mulan are another. Even modern children's tv has echoes of the idea...look at "Wendy Wu Homecoming Warrior" and Kitara the powerful "water bender" of Avatar: The Last Airbender. It isn't just a female archetype. Look at the men in martial arts who also have an artistic or philosophical expertise to balance their martial skill, like calligraphy, poetry, or philosophy...Bruce Lee is a wonderful contemporary example. Rhodes scholars who excell at both sports and academics are another.
Successful examples of yin and yang in balance are all around. It is easier said than done, I grant you. But anyone can tap into that energy...finding that balance may be challenging, but the benefits make the effort well worth it.
Wishing you both yin and yang power...in exquisite balance.