AKJV(i)
16 When I applied my heart to know wisdom, and to see the business that is done on the earth: (for also there is that neither day nor night sees sleep with his eyes:)
17 Then I beheld all the work of God, that a man cannot find out the work that is done under the sun: because though a man labor to seek it out, yet he shall not find it; yes farther; though a wise man think to know it, yet shall he not be able to find it.