What does Ecclesiastes 2:1-11 mean?

I said in my heart, “Come now, I will test you with pleasure; enjoy yourself.” But behold, this also was vanity. I said of laughter, “It is mad,” and of pleasure, “What use is it?” I searched with my heart how to cheer my body with wine—my heart still guiding me with wisdom—and how to lay hold on folly, till I might see what was good for the children of man to do under heaven during the few days of their life. I made great works. I built houses and planted vineyards for myself. I made myself gardens and parks, and planted in them all kinds of fruit trees. I made myself pools from which to water the forest of growing trees. I bought male and female slaves, and had slaves who were born in my house. I had also great possessions of herds and flocks, more than any who had been before me in Jerusalem. I also gathered for myself silver and gold and the treasure of kings and provinces. I got singers, both men and women, and many concubines, the delight of the sons of man. So I became great and surpassed all who were before me in Jerusalem. Also my wisdom remained with me. And whatever my eyes desired I did not keep from them. I kept my heart from no pleasure, for my heart found pleasure in all my toil, and this was my reward for all my toil. Then I considered all that my hands had done and the toil I had expended in doing it, and behold, all was vanity and a striving after wind, and there was nothing to be gained under the sun.

English Standard Version (ESV)