Even the person who masters a subject will admit to themselves (and perhaps another) that they are not the master of the subject. Rather the subject is their master.
The painter who with persistence seeks to perfect technique, dedicating every aspect of self to stroke and media, will look at the skill of another devoted aficionado, seeing something new and unknown that they must master. The ever pursuit of perfection turns them into a slave of inner demands.
The entrepreneur who with gall and effrontery seeks to dominate an industry, dedicating every aspect of self to dominance and control, will look at the prowess of another business and sees something demanding acquisition. Every pursuit of dominance turns them into a slave of inner demands.
The wise who is determined to excel in knowledge and understanding, dedicating every thought to wisdom, will find new information demands new perspective and intelligence. The ever pursuit of wisdom they will eventually admit is beyond them. If they do not admit, “Whatever wisdom may be, it is far off and most profound, who can discover it?” (23-24) they will be buried in a hole of despair.
Solomon the wise who descended into this valley miffed with waning strength, “I turned my mind to understand, to investigate and to search out wisdom and the scheme of things, and to understand the stupidity of wickedness, and the madness of folly… Meaningless, utterly meaningless.” (25)
Solomon sought to understand the human soul, what drives a person living under heaven discovered the truth that many who believe in life apart from God is chasing after the wind. He discovered that he was chasing after the wind. His life had been meaningless. He had discounted the truth of God and accepted a lie.

Who can rescue the human soul? Thanks be to Jesus and the power of salvation he rings.