It is appropriate that the figure on the Rider-Waite Eight of Cups is walking near a marsh or pool, because a stagnant swamp is the best symbol for the emotional stagnation portrayed here. This happens when the flow of energy and love that pushes us forward stops, and when you simply start drifting through life on the placid ocean, waiting for the wind to return. In such times, waiting is usually not the best solution because it is unlikely that anything will get done if you just sit there. This is one of those times when you might just have to break out the paddles and row.
Recognizing when it is time to move on, away from difficult times, is the primary theme of the Eight of Cups. Since it is a Cups card it refers mainly to relationships, those where you are giving too much and not getting nearly enough in exchange. A one-sided relationship of this type will cause you nothing but pain for as long as it lasts, and when the Eight of Cups appears in a reading relating to such a relationship, it is a powerful wake-up call that cannot be ignored. Take a look at your situation and see what can be done to balance things out a little.
Another type of energy stagnation illustrated here is simple lethargy, the lack of motivation and desire to achieve. Such apathy generally manifests as complaining about how good the past was and how bleak the future looks. The lesson the Eight of Cups gives us in this case is this: the past is gone and it cannot be changed, so you might as well make the most of the future. You cannot go backward and you cannot stay where you are, and the time has come for you to move on. This is in many ways a card of self-discovery, urging you to pursue your true path and find something better. An old ambition may have to be abandoned but a new one will certainly arise.
Tying into this theme, and usually fitting with the card’s symbolism, is the notion that physical sacrifices must be made for spiritual growth to happen. Just look at the card again: the man walks away from his eight golden cups, neatly stacked, to the barren wasteland ahead. This represents a search for higher truth when the everyday truths of the material world are no longer sufficient to satsify the soul. In many ways the Eight of Cups is tied to the Hermit and the Hanged Man, who give up their friends and their freedom, respectively, to seek wisdom. The sacrifice intended on the Eight of Cups comes from the heart, but the wisdom earned fills the void that is created.