Mark Zuckerberg, born on May 14, 1984 in America, was good at computer, and now is the boss of Facebook. He married Priscilla Chan and had a daughter. In only 8 years, Zuck made his small website into a world famous one. Zuck once wrote to his friends, "Life is not always easy. You should always keep your dream and work hard."

Nick Vujicic was born, without arms and legs, in 1982 in Melbourne, Australia. Nick met all kinds of difficult things in his life. But he never gave up. Now Nick has his own company. He likes to tell his life story to people. He says attitude is the most important in life and it can help you be successful.

The famous scientist and thinker, Charles Darwin, was born on February 12, 1809, in England. As a boy, Charles liked to go for walks in the forests. He enjoyed watching trees, flowers, animals and comparing what he saw with everything he had read in science books. In 1859, Darwin finished his famous book The Origin of Species and the book changed the world a lot.