Ecclesiastes 2:23

2:23 For all day long his work produces pain and frustration,

and even at night his mind cannot relax!

This also is futile!

Ecclesiastes 8:9

8:9 While applying my mind to everything that happens in this world, I have seen all this:

Sometimes one person dominates other people to their harm.

Ecclesiastes 11:10

11:10 Banish emotional stress from your mind.

and put away pain from your body;

for youth and the prime of life are fleeting.