Kane's saga depicts the superficial element of the American Dream in his creation of a vast business empire. The deeper message of the film, however, is that the dream is just that—an illusion of sorts in which Kane accumulates money and power but doesn't understand how to use them properly. He believes, mistakenly, that wealth facilitates total power, and he's unable to see that no matter how rich and successful a man becomes, he cannot control other human beings or even create fulfillment and happiness for himself.
Two elements among many illustrate this theme of illusion. Kane tries to make his wife into an opera singer although she has absolutely no talent. All he ends up doing is exposing her, and himself, to ridicule. Though practically every scene in Citizen Kane is legendary among film buffs, the famous ending stands out. After Kane's death, his possessions are being sorted out. "Throw that junk!" a man directs the workmen, and Kane's childhood sled, which we now see is the "Rosebud" of Kane's last word, is cast into the furnace, going up in smoke with everything else. The symbolism is that Kane's (and by extension, everyone's) Dream has been to recreate the happiness of childhood. But for him, it was impossible, and the last shot, of smoke rising from the furnace, shows the impermanence, or the illusion, of whatever success the Dream was capable of giving him.