Life swings, Schopenhauer tell us, like a pendulum backward and forward between pain and boredom. Between those two poles are joy. IE. there are far more pain and boredom in life than joy. Or to put it in another way, If life is like that, there is always far more work than joy and pleasure and when we finally (and seldom) are satisfied, we quickly moves to a state of boredom.
In a cruel way, Schopenhauer is absolutely right but - as the thinker I was quoting says - this does not - nessesarily - mean that he cannot be wrong also.
Does that make sence?