Well, life is vanity anyway.
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.
and later in the same chapter
22 What has a man from all the toil and striving of heart with which he toils beneath the sun? 23 For all his days are full of sorrow, and his work is a vexation. Even in the night his heart does not rest. This also is vanity.