Solomon
Ecclesiastes 2:15ESV·traditional attribution

Then I said in my heart, “What happens to the fool will happen to me also. Why then have I been so very wise?” And I said in my heart that this also is vanity.

Matthew Henry Presbyterian @wholebiblehenry

Solomon having tried what satisfaction was to be had in learning first, and then in the pleasures of sense, and having also put both together, here compares them one with another and passes a judgment upon them. I. He sets himself to consider both wisdom and folly.

Commenting on Ecclesiastes 2:12-16

John Gill Reformed Baptist @doctorgill

Then said I in my heart, as it happeneth to the fool, so it happeneth even to me,.... The wisest of kings, and the wisest of men; that is, he looked over things in his mind, and considered what had befallen him, or what were his present circumstances, or what would be his case, especially at death; and said within himself, the same things happen...

Jamieson-Fausset-Brown Reformed @jfbcommentary

why was I--so anxious to become, &c. (Ch2 1:10). Then--Since such is the case. this--namely, pursuit of (worldly) wisdom; it can never fill the place of the true wisdom (Job 28:28; Jer 8:9).