By His Divine Grace A.C.B. Swami Prabhupada
Every living being is ambitious to have the topmost level of enjoyment in the material world and yet he is always unhappy here. This unhappiness is present in all the above mentioned planets in spite of long life and standard of comfort more and more increased. That is the law of material nature. You can increase the duration of life and standard of comfort to your highest capacity and yet by the law of material nature you shall feel unhappy; the reason is that the quality of happiness which is compatibly suitable for our very constitution is different from the happiness derived from material adjustment. The living entity is a minute particle of Sachidananda Vigraha and therefore he has proportionately the necessary propensity for joyfulness which is spiritual in quality but he is vainly trying to derive it in a foreign atmosphere of the material nature.