Seeing the futility of pleasure and the building of great works, Solomon looked at those who had human wisdom, including himself, and the results in this life to the person who has become known for his wisdom. He expressed the situation that he then faced:

“I myself said in my heart: ‘An eventuality like that upon the stupid one will eventuate to me, yes, me.’ Why, then, had I become wise, I overmuch so at that time? And I spoke in my heart: ‘This too is vanity.’ For there is no more remembrance of the wise one than of the stupid one to time indefinite. In the days that are already coming in [as a person ages], everyone is certainly forgotten; and how will the wise one die? Along with the stupid one.”​—Eccl. 2:15, 16.

So, even though an objective may be commendable, a pursuit of it to the point of neglecting our own really important interests, not allowing ourselves time or opportunity to think of what God has in mind as to mankind’s future, actually ends up in vanity. Certainly the world goes on unthankful, and eventually forgetful and unappreciative. And finally the individual has gone out of existence.