Jamieson, Fausset and Brown on Ecclesiastes 1:15

15. Investigation (Ec 1:13) into human ways is vain labor, for they are hopelessly "crooked" and "cannot be made straight" by it (Ec 7:13). God, the chief good, alone can do this (Is 40:4; 45:2).

wanting--(Da 5:27).

numbered--so as to make a complete number; so equivalent to "supplied" [Maurer]. Or, rather, man's state is utterly wanting; and that which is wholly defective cannot be numbered or calculated. The investigator thinks he can draw up, in accurate numbers, statistics of man's wants; but these, including the defects in the investigator's labor, are not partial, but total.