Ecclesiastes 1:12-17

I the Preacher have been king over Israel in Jerusalem. And I applied my heart to seek and to search out by wisdom all that is done under heaven. It is an unhappy business that God has given to the children of man to be busy with. I have seen everything that is done under the sun, and behold, all is vanity and a striving after wind. What is crooked cannot be made straight, and what is lacking cannot be counted. I said in my heart, “I have acquired great wisdom, surpassing all who were over Jerusalem before me, and my heart has had great experience of wisdom and knowledge.” And I applied my heart to know wisdom and to know madness and folly. I perceived that this also is but a striving after wind.