"Go, eat your food with gladness, and drink your wine with a joyful heart, for it is now that God favors what you do. Always be clothed in white, and always anoint your head with oil. Enjoy life with your wife, whom you love, all the days of this meaningless life that God has given you under the sun - all your meaningless days. For this is your lot in life and in your toilsome labor under the sun. Whatever your hand finds to do, do it with all your might, for in the grave, where you are going, there is neither working nor planning nor knowledge nor wisdom." NIV translation
This passage speaks of the rich and the fact that they can enjoy the things of this life but, at the end of their days, they still go to the grave. If you believe that this world is all that there is, then, you will work at it to get the most out of it. There are those who spend their entire life trying to get more so that they can stay ahead of others and be considered "successful".