These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
It's lampshaded several times in the first part, that Sancho Panza is a sane man with a very limited intelligence. In the second part, through fifty chapters, we'll see him display his common sense.
In Part II, Chapter XI, Don Quixote claims: "from a child I was fond of the play, and in my youth a keen lover of the actor's art". Several critics have toyed with the idea that Don Quixote never lost that passion for theater and behaves like an actor: he does not believe to be a knight, but pretends to be one, as if he's on stage.
Indeed several critics in the 20th Century notably writer Harold Bloom has argued that Quixote is in fact sane and rational and is putting on an act at being crazy to show the absurdity of society. This is borne more in the melancholy Part 2, where Quixote discovers that he has become a cliche in his own lifetime and a Living Legend much like the great heroes of the past he hoped to emulate.
Man of La Mancha is the best display of the school of thought that idealizes Quixote, though arguably Fan Wank because of it.
Let's be fair, though: A lot of people like to point and giggle at Quixote's insanity, but a lot of them would also love to have a hallucination that elaborate, assuming they could recover. Why else would we have games like The Legend of Zelda or Final Fantasy?
If you are an Hispanist or a Spanish Literature student, you'll know that's not even the tip of the iceberg when discussing alternative interpretations of The Quijote and its characters, particularly the titular character, Sancho and Dulcinea. Even in the same books, the characters don't stay the same. The most accepted characterization changes through history as well. From a funny loon in its original time, to an Idealistic or a Romantic hero on Modern times, etc.
Applicability: Literary critic Harold Bloom's wrote in his article,''The Knight in the Mirror'':"The aesthetic wonder is... when we stand back from the huge book and ponder its shape and endless range of meaning. No critic's account of Cervantes's masterpiece agrees with, or even resembles, any other critic's impressions. Don Quixote is a mirror held up not to nature, but to the reader. How can this bashed and mocked knight errant be, as he is, a universal paradigm?" That means that every reader will interpret Don Quixote in his own way, and all of those interpretations will be valid. It also means that none of them could be valid, because every reader’s impression of himself is reflected by the novel. You can interpret all other novels, but in Don Quixote's case, the novel interprets YOU!!.
Even Better Sequel / First Installment Wins: Part II is considered deeper and more mature than Part I, but the most well-known and influential episodes (like the windmills) come from the first part. Indeed its Don Quixote's first sally with Sancho Panza.
Quixote: Man who fight for love of the ideal. Man who fight for noble causes
Maritornes: A rude, ugly and mannish maid.
Rocinante: Horse thin and weak, almost always full of sores. This one was even documented by Cervantes in the Part II, Chapter III, when Carrasco declares that the first part of the novel got read…
" by heart by people of all sorts, that the instant they see any lean hack, they say, 'There goes Rocinante.'"
Dulcinea: the name Don Quixote gives to the (blissfully unaware) woman he has made himself the champion of. In the Spanish of the time, Dulcinea meant something akin to an overly elegant "sweetness". To this day, to refer to one's "Dulcinea" is to refer to the object of one's hopeless devotion and idealized love.
Most native Spanish speakers who have completed high school can quote the first few lines by heart.
Romantic writers lionized Don Quixote as a praise of hopeless noble ideals in an increasingly cynical and materialistic world. Then, followers of literary Naturalism praised the novel... for deconstructing groundless Romantic enthusiasm.
Take a Third Option: Some people argue that Don Quixote himself is more complex than either division, and that he's essentially a tragic figure who willingly chooses to go insane rather than live his banal life and that by willingly embodying outdated and chivalric ideas which probably never existed in a world of consequence, he's paradoxically more heroic than Amadis of Gaul or Lancelot or as heroic as the legends he hopes to emulate. This makes him a modern day existentialist hero.
Mis-blamed: Even many fans of They Might Be Giants assume that the band took their name directly from this novel. It actually comes from the 1971 movie They Might Be Giants, whose main character (who believes himself to be Sherlock Holmes, and has been compared to Don Quixote by another character) muses on the value of being open to the possibility of windmills being giants. Don Quixote himself had no such doubts; he was positively certain that he was charging against giants.
"No, senor, that's not true," said Sancho, "for I am more cleanly than greedy, and my master Don Quixote here knows well that we two are used to live for a week on a handful of acorns or nuts. To be sure, if it so happens that they offer me a heifer, I run with a halter; I mean, I eat what I'm given, and make use of opportunities as I find them; but whoever says that I'm an out-of-the-way eater or not cleanly, let me tell him that he is wrong; and I'd put it in a different way if I did not respect the honourable beards that are at the table."
Romantic Plot Tumor: The last chapters of the First Part solve the Love Dodecahedron between Dorotea, Don Fernando, Lucinda, Cardenio, Clara and Don Luis, leaving Don Quixote as a mere spectator in his own book. In the Second Part Cervantes makes a Author's Saving Throw when Don Quixote opines:
Signature Scene: Don Quixote charging against windmills believing they are giants.
Surprisingly Improved Sequel: Although Don Quixote is published as a one volume today, it is generally agreed that the mostly philosophical second part is better that the mostly farcical first one.
Perhaps related to the fact that the first part was written while Cervantes was in jail (Sancho Panza's wife has 2 different names in the same page, none which would be the definitive Teresa Panza).
Values Dissonance: Several of the attitudes expressed by the characters are enough to make modern sensibilities cringe. Sancho, a man usually associated with being a loyal and amiable sort actually considers taking up selling people as slaves and turning 'black into gold'.
Values Resonance: Don Quixote’s Satire will live as long as the justice system is made of human judges capable of corruption that let criminals go for a price. Or as the people who direct The Government only care about ruling the people without making any effort to enhance the live of his subjects. Or while the Moral Guardians are useless. Or while there are people who fanatically defend any kind of entertainment work no matter its faults. Those examples are only a few of the issues the book attacks.
Weird Al Effect: Barring a few exceptions such as Tirant lo Blanc (which is remembered for being one of the first literary texts written in Catalan/Valencian, and has a recent Film of the Book made of it) few people today remember the novels that Don Quixote read and Cervantes lists before throwing them in the bonfire in Chapter 3, and most of them are philologers and historians. One of those novels is remembered today in the USA, sort of: a land conquered for Spain got named for a character in one of those novels - the nymph California.