The false self believes that it needs to acquire external things (possessions, accomplishment, admiration, thrills), so it derives its identity from a constant sense of lack, which produces desire and results in seeking. It thus needs a sense of discontent for its very existence. If it were to be completely satisfied, it would cease to exist. Discontent is its fight for life.
The vast majority of our time and effort is spent pursuing everything from money to sex to approval to victory. On those infrequent occasions when we get what we were after – cash, an orgasm, applause, winning a game – our sense of lack disappears. For a few moments we are contented. There is no desire and we are not pursuing anything. We experience joy and peace because the ego deflates and the true self is not obscured by discontent, lack, or desire.
Eventually the thought process of ego returns. It is, by definition, discontent, so it once again foments feelings of lack and desire. Whatever we were contented with just minutes before no longer satisfies because the true self is once again clouded over by ego. We then seek the next possession, the next relationship, the next problem to solve, the next pleasure.