The Seven of Cups often appears when a difficult choice must be made, and the image on most versions of the card reflects that. The seven cups are filled with strange and wonderful gifts... but there is always danger hidden within one or two of them to sting anyone who ventures near. Lying amidst the gems and the wreath of victory are a snake and a dragon. Sometimes you have to choose between many options, all of which may be tempting but only one of which is the best choice. At others times not all of those choices are real options at all; they are delusions of the imagination.
This card generally shows choices and plans that have little or no basis in reality. Such things are typical of the developed imagination, and fine if they stay in the imagination. But when you try to implement those ideas in the real world you are leaving yourself open to inevitable disappointment when you realize that your vision simply does not work. The fortress has no foundation and it will fall with the first enemy attack. Some attainment is indeed possible, but like the sword of Damocles, the inevitability of defeat lingers over your head, waiting to drop and shatter all those castles you have built in the clouds.
Temptation is another theme of this card, and with so many choices presented it would be easy to be swayed to that cup containing the snake of jealously and cunning. Since this card is of the Cups suit we get all the sexual and emotional connotations of temptation; the one-night stand, the extramarital affair, and all those other things that seem innocent and pleasurable at the time they are undertaken. But in the vast majority of cases, the pleasure gained temporarily is far outweighed by the consequences that last, in most cases, for an entire lifetime.
In short, the Seven of Cups is a sign to be vigilant in everyday life. Be on guard against temptation, and before taking any offers be aware of all the potential ramifications. Keep a close eye on your dreams so that they do not get too farfetched and fantastic. When faced with many choices, all of which seem equally attractive, turn to your intuition for guidance. If you still don't know which to take, it might be safer to not take any of them at all! Better to leave the gems than plunge one's hand into a cup full of snakes. If your ethics are questioned, do not go against them, but stand true to your beliefs. Keep your feet on the ground, and your head out of the clouds.