It has been proven time and again how biased a lot of the history we learn about today is. The longer a story takes to be told the more distorted it gets by individual opinions, ideas and assumptions. The only unbiased history we come across usually come from the primary sources, which could be a photograph, letter or any document that comes from a person who was present at the time of the event or was directly involved. A secondary document on the other hand is one which comes from a source that has learned about the event from a primary source or another secondary source. Our emotions are often the reasons why these stories get changed. And sometimes it is ego that dominates the desire of what people want others to know. A lot of times people also add things on their own because they forget parts of what they had heard. Therefore not all stories we learn from different sources can be trusted, because history gets distorted, slightly or significantly, but it does.