We both want desperately to know so much more than we know, and we are unable to see some things that are hidden.
But that's exactly how God designed it.
From the ESV Study Bible notes on Ecclesiastes 3:11
"The Preacher thus realizes that both his desire to understand all of life, as well as the limitations of his ability to do so, have been ordained by God."
"...then I saw all the work of God, that man cannot find out the work that is done under the sun. However much man may toil in seeking, he will not find it out. Even though a wise man claims to know, he cannot find it out."
That will help with our frustration, a little, and give us a good sense of humility, but we won't stop seeking. We can't stop. I don't want to stop. So there it is.