I was watching a documentary the other day of a person from history called Chiune Sugihara. Not many have heard of him. But during the second world war, he helped many jews escapes the Nazi terror. You can read about Sugihara's efforts here and here. The show highlighted his strict upbringing in a Japanese society with the principles of Samurai warriors, his student days and his work with the government. The show also focused on the effort by the escaped jews years later in locating Sugihara to thank him personally. After many many many years, one of the escapees whom he had helped, found him in Russia and asked him why Sugihara had put his life on the line and did all that hard work of helping thousands of Jews escape when everyone else refused across the world.
And he said : " When you get a chance to do good, you go ahead and do it. Then you leave it alone. And forget about it. You don't write and publicize it "
That tireless effort of Sugihara helped those thousands of people escape who in turn worked hard and built themselves into a community of 50,000 that survives to this day producing some of the world's best engineers, architects and businessmen. When you do good to a single person, you are in fact changing and helping the lives of thousands of people. So if you want to change the world, start by doing good to one person.