In "Don Quixote," Miguel de Cervantes serves as both a satire and homage to the classic chivalric tales. The story follows an old man named Alonso Quixano, who loses his sanity after reading too many chivalric romances and decides to become a knight-errant. Adopting the name Don Quixote, he embarks on various adventures with his loyal squire, Sancho Panza, where he confuses reality with his fantasies of heroism.
Cervantes reflects on nostalgia and the transformation of values through his protagonist's melancholic reminiscence of past glories. The phrase "what had been when it was Rocín, before what was now" captures this sentiment of longing for a noble past, indicating how Quixote's visions of knighthood stand in stark contrast to his present reality filled with absurdity and disillusionment. This underscores the theme of illusion versus reality in the novel, as Quixote's misguided ideals drive him to confront the world in a unique yet comical manner.