This prayer from pastor and author, Bo Giertz, provides a clue:
I notice, Lord, that when I'm down and tired of life, it's because I've tried to live without You. If life becomes meaningless, it's because I've tried to find a different meaning than the only right one, the one that comes from You. When I make my own plans and decide what I want to have, when I want to profit and be happy and receive appreciation for my own gains, then it seems meaningless...when I'm happy to do something for You at Your side, then there's always a purpose in every day and a purpose in every task that lies before me. Amen.