You Cannot Predict God's Works

In the 11th chapter from the book of Ecclesiastes, most of it speaks on dividing your investments across many different areas because one never knows where the most profit will come from.  It also speaks to farmers predicting the weather, to find out when to place their seeds.  This is meaningless as one can never predict when it will be the best.

The last three verses are about finding joy and not to worry.  It is best to enjoy life, especially in one's youth, but not to be too careless because in the end you will have to account for it in the eyes of God.