4 ideas
Seventeen-year-old Fabrice del Dongo runs away from Italy to fight for Napoleon and reaches the field of Waterloo. He drinks brandy from a canteen-woman and gets separated from the troops he joins. He is later robbed of his horse by his own side, and he glimpses marshals gallop past without being sure who they are. Afterward he cannot decide whether what he witnessed was a battle at all, or whether he truly took part in Waterloo.
A great historical event does not appear as one event to anyone inside it. To each participant it is a series of noises, smoke, rumors, and small humiliations with no visible shape. Coherence such as 'the battle of Waterloo' is imposed afterward by bulletins and historians, so on-the-ground testimony and official narrative are two different kinds of knowledge rather than better and worse versions of the same one.
Fabrice arrives at war carrying heroic images drawn from books and Napoleonic legend. He keeps measuring what happens against those images, asking 'Is this a real battle?', instead of registering what is in front of him. A strong prior script about what an experience should feel like makes a person miss, or disbelieve, the experience as it actually occurs.
In the small principality of Parma, power flows entirely from a fearful prince's moods. Laws, prisons, and pardons therefore become tools in a game played by ministers and mistresses. Outcomes such as Fabrice's imprisonment in the Farnese tower turn on personal vanity, rivalry, and leverage rather than justice, so skill at reading the ruler's fears matters more than merit or innocence.