That is just your perspective of an event that was of extreme importance to you. How might the perspectives of other people who witnessed (or could have witnessed) that particular event color their memories of it? How might they write it down? Between all of the people who witnessed it (or could have witnessed it), which details are most likely to be agreed upon by everyone? What details might only have been noticed by a few due to their location and proximity (let alone their attention or lack thereof)? How might each person's personal beliefs and biases color their memories of the parts of the event that they witnessed?
Understanding events from history is a type of detective story, building up evidence that helps the historian understand the major parts of an event. Unfortunately, it is impossible to know the entire Truth. All of the reporters of an event have their own perspective--not to mention their own agenda--which can change the texture of any given moment in time. What historians try to do is gather enough information from as many sources as possible to piece together some semblance of the actual person, place, or event that is being studied.
While knowing that there will always be pieces missing can be quite frightening, it's also part of the joy of being a student of history--there is always more that can be discovered.