1. It is impossible to know whether a person deserved happiness or suffering because you can never know the intentions behind their actions
  2. Even if you should make others happy, there is no way to precisely know how to make others happy
  3. What constitutes suffering or happiness in one-moment is unclear. It may be that a heartbreak for you is the best thing to happen to you
  4. Thus, the only way to improve the world is to improve ourselves - where he have some certainty that things are getting better or worse

By following self improvement, you promote others to follow in your footsteps.