Good people do good things, and think of what they did as unremarkable.
That's happened a lot.
Not so good people do some volunteering and have to take a load of selfie and post it to FB and Instagram. This is more like a ego boosting, self centered act. Of course, society need these people to fill the gaps of social needs. But are they really good people, or using other people vulnerability to make themselves feel good?
The really good people who "just do good" without giving much thoughts, or attention to themselves. If you ask them for motivation, they might not give you any, as they haven't really thought about it before they act.
Doing good is so natural that it does not need motivation. That's how I feel about do any volunteer work.
"Joseph C., who escaped from the death facility at Treblinka, wept in his testimony when he tried to describe the one Pole who helped him in his distress. The word that he finally found to describe Szymon Calka was “humanity.”
This looks like a really cool book.