In the exchange between Sancho Panza and Don Quixote, Sancho observes that there are many people who walk the earth. This reflects the notion of the commonality of humanity, as most individuals go through daily life without significant distinction.
Don Quixote counters Sancho's observation, asserting that while many may be physically present, only a select few can truly be considered gentlemen. This highlights the difference between mere existence and the qualities that define honor, nobility, and character in a person.