(1) The Last Test, what does Pleasure accomplish?

“I said to myself, “Come now, I will test you with pleasure. So enjoy yourself.” And behold, it too was futility. I said of laughter, “It is madness,” and of pleasure, “What does it accomplish?” (Ecclesiastes 2:1 – 2)

(2) Last Pleasure Sins

“All that my eyes desired I did not refuse them. I did not withhold my heart from any pleasure,…” (Ecclesiastes 2:10, including both sinful & non-sinful pleasures because it’s stated ‘any pleasure’ with respect to ‘what he desired & he certainly desired women as the verse below reveals confirms it too’, “concubines”):

“Also, I collected for myself silver and gold and the treasure of kings and provinces. I provided for myself male and female singers and the pleasures of men– many concubines.” (Ecclesiastes 2:8)

*At the time of penning those verses, the “Preacher” must have stopped all these sins & is reflecting back on its “vanity” (pointlessness).

(3) Risky Wisdom in The Last Fall

Though he fell into sin, was Wisdom taken away from him?

No! As this verse reveals:

“… Also my wisdom remained with me.” (Ecclesiastes 2:9)

Why?

A possible reason may be due to this ‘principle’:

“for the gifts and the calling of God are irrevocable.” (Romans 11:29)

(4) An Advantage after quiting sin & being spared of its consequences by God’s Mercy (if it applies in your case too as it did with the “Preacher”):

You have a second chance.

Also, say regarding ‘marriage’, here’s a plausible interpretation:

(i) The woman who still desires to ‘marry you’ despite your awful past must really have a ‘heart filled with God’s Love’ without which it is impossible to ‘forgive’ or accept such a person. Then it is highly possible that God’s Will is for you to marry her (all other factors held constant).

(ii) If ‘no woman’ desires to marry thee after all these, then it’s easier to determine God’s Will in this case to be for you to “remain unmarried” (both as a punishment & your advantage, spiritually).

This is how I see it. Time will tell. And it’s a way where there’s always “hope” in Him regardless of any mistakes done in the past provided one “repents truthfully & remains as it is”.