Ecclesiastes 2:20-23

So I gave up in despair, questioning the value of all my hard work in this world. Some people work wisely with knowledge and skill, then must leave the fruit of their efforts to someone who hasn’t worked for it. This, too, is meaningless, a great tragedy. So what do people get in this life for all their hard work and anxiety? Their days of labor are filled with pain and grief; even at night their minds cannot rest. It is all meaningless.