New Revised Standard Version
Then I said to myself, “What happens to the fool will happen to me also; why then have I been so very wise?” And I said to myself that this also is vanity.

Contemporary English Version
Finally, I said to myself, "Being wise got me nowhere! The same thing will happen to me that happens to fools. Nothing makes sense.

New American Bible
So I said in my heart, if the fool’s lot is to befall me also, why should I be wise? Where is the profit? And in my heart I decided that this too is vanity.

Douay-Rheims Bible
And I said in my heart: If the death of the fool and mine shall be one, what doth it avail me, that I have applied myself more to the study of wisdom? And speaking with my own mind, I perceived that this also was vanity.

And I said in my heart: If the death of the fool and mine shall be one, what doth it avail me, that I have applied myself more to the study of wisdom? And speaking with my own mind, I perceived that this also was vanity.

even to me

Ecclesiastes 1:16,18 I have spoken in my heart, saying: Behold I am become great, and have gone beyond all in wisdom, that were before me in Jerusalem: and my mind hath contemplated many things wisely, and I have learned. . . .

1 Kings 3:12 Behold I have done for thee according to thy words, and have given thee a wise and understanding heart, in so much that there hath been no one like thee before thee, nor shall arise after thee.

then

Ecclesiastes 1:2,14 Vanity of vanities, said Ecclesiastes: vanity of vanities, and all is vanity. . . .