The entire superhero tradition began with the first appearance of Superman in Action Comics #1, and ever since that moment, he has been a beacon lighting the way for others. In the eighty years since his first appearance, the Man of Tomorrow has had to change quite a bit to keep up with the changing times.
Despite that, his personality has become very well defined. Many people who do not even read comics still have an intimate knowledge of the Kryptonian hero, prompting dialogues about his attitudes and behavior. While Superman's personality makes him a paragon of virtue, there are some aspects to it, which are really just awful.
As a hero who regularly works to save lives and save the world, Superman must ultimately believe that things can be saved. To be a hero, he cannot give in to despair.
With his superpowered senses, he hears the suffering of people in pain, sees the world's horrors, and yet still chooses to believe in good. Because he also hears the small kindnesses that people do to one another and thinks these are the more important. This is part of what makes him a hero.