Everyone is misguided, everyone is acting in this world under the bodily concept of life. And they are very very much unhappy on account of this. Because as soon as one understands that "I am not this body," he immediately becomes Brahma-bhutah prasannatma. Prasannatma means, what do you mean by prasannatma? Na socati na kanksati [Bg. 18.54]. No more material desire. That is brahma-bhutah. Everyone is trying for material sense gratification -- the animals, the beasts, the birds, and the human being. That is material world. He is simply socati and kanksati. When there is loss he is crying, and when there is no possession he is hankering. These are the two diseases of material existence.
By H.D.G. Srila Prabhupada