For my 42nd birthday, my wife read Psalm 42 to us. Not one we may have particularly thought appropriate for a birthday: It's a Psalm about feeling downcast and forgotten, and longing and thirsting for God.
The sad truth is we often only remember our thirst for Christ when we are troubled! But isn't He the Only fountain of Life, whether in the good and bad? Perhaps in the "moment of downcast heart" we are more blessed – because there we are reminded of and drink anew the True Life of Christ.
Let's remember Him when the living is pleasurable too!
Why are you cast down, O my soul, and why are you in turmoil within me? Hope in God; for I shall again praise him, my salvation (Psa 42:5)