11 He has made everything appropriate in its time. He has also set eternity in their heart, yet so that man will not find out the work which God has done from the beginning even to the end.

Not only has God bestowed on people the occasions of life, but God also places the desire to learn and find value in them, We have seen the Qohelet lamenting, “16 For there is no lasting remembrance of the wise man as with the fool, inasmuch as in the coming days all will be forgotten.” We do not and cannot know the seasons of eternity, yet our heart desires them. God knows the begining, all that has passed, and the end, all that will come. God has and will make all the times of eternity, just as He wills.

In passing, It should be noted, God has access to the heart.

12 I know that there is nothing better for them than to rejoice and to do good in one’s lifetime;
Again we are told to rejoice in the good that God provides in the midst of the cycles of life, “there is nothing better”
13 moreover, that every man who eats and drinks sees good in all his labor—it is the gift of God.
To appreciate the gifts of God we need to enjoy the fruit of our labor and recognize it is from God.
14a I know that everything God does will remain forever; there is nothing to add to it and there is nothing to take from it,
From the beginning to the end, all of the works of God will הָיָה haw-yaw – fall out, happen, come to pass, occur take place. There is a certain, final statement. For me, I see a certainty that God does what he wills more than I see a remaining forever. I say this because as a Christian, my views of last thing is different than what is seen in Ecclesiastes. In Ecclesiastes the grave is the end. This eterninty bound in the heart is the closest thing in Ecclesiastes to a resurrection hope.

The final section of Isaiah is one of the clearest Old Testament areas relating to the end of this time. I bring this up because the current earth will not remain. “17“For behold, I create new heavens and a new earth; And the former things will not be remembered or come to mind.”

14b for God has so worked that men should fear Him.
God has provided all cycles of life. We have a very limited life compared to God. Further, we can fall short in trying to accomplish what we want, God brings all He desires to actualization. This should cause us to loot to God with awe.
 15 That which is has been already and that which will be has already been, for God seeks what has passed by.
God will again create the cycles that have passed.