Everyone uses
different criteria to decide what makes someone a
hero.
As for myself, I imagine the person and see if the following apply:
This person has qualities that I admire, that I see as noble.
Reading this person's autobiography would be fun.
I would enjoy having lunch with him or her.
I can consider this person in their totality. They're not perfect, but no aspect of their character disgusts me.
If I turned out like this person, I wouldn't be disappointed