I’ve always said: “Never let the truth get in the way of a good story.”
When basing screenplays on biography or events from your own life, Syd Field says
You can use this particular experience as the starting point in your story, but as you go through the preparation process, you’ll find that you want to hold on to the “reality” of the experience; you want to be “true” to the situation or incident. Most people find it hard to let go of the experience. But often, you’ve got to let “reality” go in order to dramatize it more effectively.
I liken it to climbing a staircase: the first step is the actual experience, the second step is increasing the dramatic potential of a story, and the third step is integrating both of the previous steps to create a “dramatic reality.” If you remain too true to “who did what” in the “real” order of the experience, it usually ends up as a thin story line with little or no dramatic impact. Do not feel “obligated” to remain “true” to reality. It doesn’t work. The “reality” of an event may, and often does, get in the way of the dramatic needs of your story.
The actual history of the event has to be maintained but you don’t have to be true to the emotional, day-to-day events, leading up to the historical incident. Just look at All The President’s Men, Ray, Erin Brokovich and JFK. History is only the starting point, not the end point.
Of course this also applies to game shows, documentaries, news reports…