People in general define truly successful people who made great contribution throughout the history, which made the world better place to live for human being. Some believe that the measure of true success of individuals is society's external rewards. Others think that true success can be defined when people content with the achievement they made. In my point of view, true success is really personal perception that themselves can only judge because it should come along with personal satisfaction.
Truly successful people should be content with their personal achievement. That is, the satisfaction is what people sets for themselves and what people really want from their field of endeavor. No matter how valuable the external reward, such as fame and wealth, may be it would be meaningless when they are not satisfied with their achievement. In addition, much greater achievement was made because of the dissatisfaction they had. For example, Albert Einstein, one of the most successful scientists at his time, was honored his contribution on photoelectric effect by Nobel Prize, the highest external reward one could get from a society. However, he did not stop researching on his major interested area, the theory of relativity, because he did not consider the achievement he made was satisfactory. Now, the theory of relativity is what general people remember of Einstein not the photoelectric effect.
Many contributions to the society were made by who devoted their lives regardless of external rewards from the society. It is a lesson from human history that many greatest thinkers are almost always out of step with their time in some extent. Many of them were against what the general public believes and kept their inclination regardless of their own safety. For example, Martin Luther King Jr. led the human right movement especially for African American in 1960's. Although he is now considered as a successful person, he was not in his time in the society's point of view. He was just one of notorious rebel rousers. However, he did not give up until he died by assassination. It is them who are truly successful in terms of the goal they set for themselves. The society has progressed by those great and truly successful people.
Some might argue that success should be measured by some standards such as external rewards that can justify success. However, the standards set by the society are sometimes not necessary objective. In fact, many external rewards are involved with public recognition, fame, and power in them. Hence, it can be categorized as a kind of success that society defined. True success, however, comes along with the satisfaction. Ironically, many people among who are considered as truly successful are often confess their life was somewhat meaningless and they regret many things that they could not do. Success without the personal satisfaction cannot be considered as true success in spite of its recognition by the society.
In conclusion, true success should be measured only in relation to the goals one sets for oneself such as satisfaction they had for the achievement. Because truly successful people did not stop their inclination regardless of their personal safe and the recognition they had at their time, the society were fulfilled with great contributions to make the world the better place to live--true success.