Life is full of polarities: light and dark; night and day; health and illness; wealth and poverty; joy and sorrow, and all of the shades in between. If you eat gourmet meals all your life, you will never know what a good meal is. You have to eat some lousy meals to know what a good meal can be. In order to make a value judgement, you have to have something to judge against.
By design, Life is learning and growth.