Try remembering the last movie you saw; how much of it can you recall?
Could you sit back, close your eyes, and recall in perfect detail every scene, every dialog?
Of course not.
So why do you assume you can do the same for the movie of your life?
Our real-life is nothing but a huge collection of random memories.
And fortunately or unfortunately, this collection of memories is easily prone to innumerable modifications thanks to both internal and external influences.