Durashaya means which cannot be fulfilled. You can hope something but it will never be fulfilled. Persons who are trying to become happy by adjustment of this material energy, they do not know that happiness cannot be achieved without approaching God.
Everyone is thinking, “I must first of all see my own interest.” But first of all try to understand what is your interest. We do not know that and we are hoping against hope, “I shall be happy in this way.” Sometimes the washerman sits on the back of an ass and takes a bunch of grass and puts in front of the ass, and the ass wants to take the grass. But as he is moving forward, the grass is also moving forward. And he thinks, “Just one step forward, I shall get the grass.” It does not know, “The grass is situated in such a way that I may go on for millions of years; still, I will not get the happiness.”
Everyone is trying, nationally, individually, collectively, “By adjustment of this material atmosphere I shall be happy.” But it is not possible. It is repeatedly said in different shastras that there is no pleasure in this material world. Furthermore, even if we agree to live without pleasure, we are not allowed to do so. In Bhagavad-gita, Lord Krishna says that the material world is not only full of miseries but also temporary [Bg. 8.15].
Even if we want to live here amid miseries, material nature will not allow us to do so. Krishna personally, the Supreme Perfect Person, is giving you knowledge. And if we are so unfortunate that we do not take the perfect knowledge—we concoct, we speculate, we create our own idea—then it is to be understood durashaya.
Ref: Srila Prabhupada’s Srimad-Bhagavatam lecture 3.25.22—Bombay, November 22, 1974