"Дон Кихот" is a novel by Miguel de Cervantes that explores the theme of idealism through its main character, Don Quixote. He is a nobleman who becomes obsessed with chivalric ideals and sets out on adventures to revive knighthood, often misinterpreting reality. His quest highlights the contrast between lofty dreams and the harshness of the real world. The story illustrates how Don Quixote's idealism leads to both humorous and tragic situations. His unwavering belief in his noble cause often puts him at odds with those around him, showcasing the struggle between imagination and reality. This conflict remains a central theme in literature and philosophy.