The story of a man who is not a hero, and whose survival depended on sheer chance and the mercy of the enemies. Only a real survivor of WWII (Polanski & Szpillman) would tell such a story, without binary good/evil, and with such restraint.
Everyone is born, but not everyone is born the same. Some will grow to be butchers, or bakers, or candlestick makers. Some will only be really good at making Jell-O salad. One way or another, though, every human being is unique, for better or for worse.