Ecclesiastes 8:15 says "So I commend the enjoyment of life, because nothing is better for a man under the sun than to eat and drink and be glad."
Note that the same verse continues with: "Then joy will accompany him in his work all the days of the life God has given him under the sun."
Many people are familiar with the saying "Eat, drink, and be merry; for tomorrow we die". To eat, drink and be merry is not an end to itself. That is not what Ecclesiastes 8:15 says. The same verse says "Then joy will accompany him in his work....". To find happiness and satisfaction in one's work is the gift of God, as we can see in the following two verses.
Ecclesiastes 5:19: "Moreover, when God gives any man wealth and possessions, and enables him to enjoy them, to accept his lot and be happy in his work—this is a gift of God."
Ecclesiastes 3:12-13: "I know that there is nothing better for men than to be happy and do good while they live. That everyone may eat and drink, and find satisfaction in all his toil—this is the gift of God."
One interesting point to note is that while a lot is said about finding satisfaction in our work and being happy with what we do, there is equal emphasis on being happy and enjoying what God has blessed us with materially. For clarity, read the all the above verses again.