I believe firmly that heroes only exist in fiction. However, Mandela was closest to being a real hero than just about anyone else who really existed.
His heroic qualities were highlighted by the ability to forgive his enemies and to see the best in humanity. PG also tries to emulate these qualities (at least in public -- believe it or not, I'm not privy to his private life.) I have tried these qualities myself and must say that, although they are laudable, they are not realistic and have landed me in far more pain and problems than if I was as I am now.
The sad truth is that human beings are stupid, lazy sacks of shit that will always look out for their own interests over that of the common good. This is why the human rights movement will ultimately fail. Unless there is a fundamental change in how human beings actually are as opposed to what we hope they might be, our species is better off becoming extinct. Better off for the planet and for all of the other species on it, that is.
We hope human beings will be like dogs -- loyal, trusting and faithful. It's too bad people aren't dogs. We would all be much better off.