The pain caused by external disasters, such as earthquakes, natural disasters, and disasters such as vehicle accidents.

The suffering caused by relationships, such as interest and concepts, and emotional conflicts in our daily life.

The first pain is unavoidable, it is doomed to accompany your life until the last minute before you die.

The second pain is uncontrollable, but to human beings, in terms of ecological balance and the survival and continuation of humanity, most likely, the benefit that this pain has brought is more than harm. The third pain is the pain that torments human beings, keeps tormented lingering for a long time.

People always struggle and lose control in the ever changing love, mutually beneficial relationships, hatred against one another, gain and loss from conflicts. Human beings wallow in their own life and not only can't escape from their emotions, but also, in their spare time, they read stories about life experiences written by others, for emotional stimuli. Most films and novels are about this kind of stories to satisfy such needs of people.

Therefore, this kind of pain is the root of life. If such a pain disappears, then most people will lose their interest in life.