Question

Schopenhauer argued that what you lack is what you desire, and that creates “pain,” while what you do not lack you do not desire, and that creates “boredom.”
This is what led him to say, “Life swings like a pendulum between pain and boredom.”
What do you think about this? How would you answer him? Is it really true that in life there is only pain or boredom, and not happiness?