v1: The wisdom of seeking God early. It is dangerous to put off our commitment to God. Change is easier when we are young; in later years the heart can grow cold, the spirit become unteachable, the mind distracted, desires perverted. We need God's strength to endure days of trouble.
This verse does not teach that the more mature cannot be converted to Christ; it is practical wisdom born of observation.
v2-5: Explaining v1, describing old age, its pains and frailties. Solomon, now an old man, looks back on his life with deep regret. He describes death and old age using a range of metaphors.
There is the gathering gloom (v2), sun, moon and stars becoming, to us, less bright. There is physical weakening, and loss of abilities and senses (v3). There is a reticence to take risks, and a tendency to stay safely at home, although sleep is disturbed, even by a bird song (v4). Burdens seem too great, pictured by the grasshopper dragging itself along (v5). Finally, death comes, man goes to an eternal home, and mourners mourn.
v6-7: One day it will be too late; these verses describe death, using more metaphors, in all its finality; we cannot return from death.
The Ganda people of Uganda have a belief that there is a rope for each person, each of a different length. One day the rope is cut, referring to the person's death.
v8: In such sorrow and regret it is no surprise that the teacher finds everything meaningless; he has nothing to bring to his people.
v9-10: The wise teacher teaches others. Diligent in study, having a commitment to truth, putting pen to paper, in writing his Proverbs; divine wisdom, but communicated in a memorable way.
v11-12: The benefit of such wise words, given by the one Shepherd. We should not neglect such, nor add to such. They are goads, well-driven nails, to hang truth on. Thus, godly learning requires discernment, and too much study is not helpful. We must learn to be effective.
v13-14: The conclusion of the whole matter. Our responsibility is to obey Him, for we are accountable to God. To fear God is to keep His commandments; godly fear leads to obedience, not to inaction.
God will judge "every deed" and "every hidden thing." All are alike to Him, who sees and knows all things. It is either a hypocrite or a simpleton who thinks he can hide himself from God. The glorious truth, found so clearly in the NT, is that Christ is our Advocate, and even before God we are clear of our sins, and acceptable before Him.