Confidences come from evidences which also come from knowledge. Logically, human lost confidences when they have no evidences that is backed up by knowledge. It is true that it happens a lot of time, especially when the evidences are untrue, contradicting, and doubting – resulting in the less certain we become. I would like to provide a true story about my own doubting in a pre-belief about a historical study in America presidential subjects. Franklin Delano Roosevelt (FDR) is often rated as one of America’s best president, along with George Washington and Abraham Lincoln. FDR won four presidential elections and directed America through the Great Depression period – creating deals as responses to the greatest economic crisis in the History of United States (US). He also faced the World War II and World War III on his period of leadership – resulting in the initiation of the development of the first atomic bomb to protect US and win from The Allies and Japan who continuously attacked US. He did it by doing a diplomatic trust between Chiang Kai-Sek (Chinese Generalissimo) , Joseph Stalin (Soviet Leader), and Winston Churchill (British Prime Minister). Looking from these perspective, we actually believe that this is the guy who brought US to victory in both World War and America’s greatest economic crisis. Evidences are printed lots of books and internet. I concluded that he is a smart, strong, ambitious, and emotionally intelligence. I would be confident and proud to present that he is indeed one of the greatest president America ever had. However, overtime as I learn more about him, there are some other perspectives that contradict my pre-belief about FDR and I become less certain about what I believe about him. Propaganda made by enemies and oppositions to alter the history have always been made. These maleficent efforts also distort both historical data and people’s confidence about what is actually happening. I also understand the reason behind his actions. There are big differences to knowing an understanding. Knowing is shallow, however, understanding is deep. Understanding is knowing the reason why does the things stated in the knowing happened. It provides extra layer of certainty to the knowledge that will be used as a basis of evidences.