A good person may always strive to better themselves, correcting themselves when in the wrong. Repentant of those wrongs.
We all know we are not perfect, so why ask it from others when we know it's impossible? It's like me insisting that you give me $50,000, when you don't even have it. What good is it going to do me if I kept asking you for that money? It's just going to be very annoying, isn't it? Always having someone asking for something you and them know is impossible.