Mom's dad was in the army, stormed the beach at Normandy, fought through the French hedgerows, the Battle of the Ardennes, the Battle of the Bulge, and liberated concentration camps at the end of the war.
I do not often follow my characters off on tangents or change my story on a whim. I have an outline which I follow quite sternly. . . for a good long while. Then it turns out in some way to be insurmountably wrong and I am forced to re-think every component. Usually at this point I throw hundreds of pages away.