In the opening chapter of "Don Quixote," readers are introduced to the central character, an aging nobleman from La Mancha who has become utterly captivated by the tales of knight-errantry he has read. His name is Alonso Quixano, but he takes on the title of Don Quixote de la Mancha as he sets out on his quest to revive the chivalric ideals that he believes are essential to society. Quixote's obsession with these romantic stories leads him to lose touch with reality, as he begins to see the world through the lens of the grand adventures and noble deeds he has read about.

The chapter delves into Quixote's background, illustrating that his life was once that of a typical gentleman, albeit one with a penchant for reading excessively. The more he reads, the more he becomes disillusioned with the mundane aspects of his life, leading him to believe he is destined for greatness as a knight-errant. His physical appearance is described humorously; he is depicted as gaunt and aging, yet his spirit is fervent and filled with purpose.

Determined to embark on his quest, Quixote dons an old suit of armor that belonged to his great-grandfather, illustrating his commitment to the chivalric code. He improvises a helmet from a barber's shaving basin, further showcasing his disconnect from reality. His horse, Rocinante, is a feeble steed, yet in Quixote's eyes, it is a noble companion worthy of a great knight.

As he prepares for his journey, Quixote sets out under the cover of night to avoid ridicule, fully embracing his role as a knight. He is motivated by a desire to protect the helpless, right wrongs, and revive the ideals of chivalry, which he believes have been lost in contemporary society. The initial tone of the chapter is comedic, as Cervantes subtly critiques the absurdity of Quixote's ambitions while also evoking sympathy for his noble intentions.

This chapter sets the stage for the adventures to come, establishing Quixote's character as a figure who embodies the conflict between reality and illusion. His relentless pursuit of chivalry, despite the impracticality of his quest, invites readers to reflect on themes of idealism and the human condition. It becomes clear that Quixote's journey will not only involve external challenges but also an internal struggle as he faces the consequences of his delusions and the harsh truths of the world around him.