I was wondering if someone might shed some light on this. It is kind of a minor thing, but it’s been bothering me.
There is a Don Juan in Spanish legend, and a Don Juan of Mexico written about by Carlos Castenada (a Yaqui sorcerer).
Is there any relation between these people? Or is it just mere coincidence? Just a common Spanish name?
It’s a coincidence, unless Castenada was trying to make an allusion to the Spanish Don Juan. Don isn’t a name, but something like “Sir” or “Mr.”, and Juan is a common Spanish name.
Arjuna34
As I understand it, “Don” is a Spanish title roughly (roughly!) equivalent to the English “Lord”. “Juan” is a Spanish equivalent of the English “John” (see also “Jan”, “Ian”, “Ivan”, “Giovanni”, etc.
So, yes, there were several "Lord John"s running around back then. The legendary Spanish one was “Don Juan Quixote”, incidentally. (I want to say that Zorro was a “Don Juan”, but I may be remembering incorrectly…)
Nevermind; Zorro was “Don Diego”. Interesting when your reading matches your posting…
“Don” doesn’t mean “Lord,” at least these days; it’s just a general title of respect. The Don Juan of legend was addressed that way because he was an aristocrat, the Yaqui sorcerer Don Juan was called that as a respected elder.
And it’s just “Don Quixote,” not “Don Juan Quixote.” I don’t believe Cervantes gave the character a first name, merely speculating that his original surname had been either Quixada or Quesada.
As explained above b everal folks, “Don Juan” means “Mister John”, more or less. So you have “Don Juan Matus”, the Yaqui Indian that Carlos Castaneda caimed to have visited (and if you believe in him you probably believe in the Easter Bunny, too). You have “Do Juan Tenorio”, the womanizer of story, play, and opera.You have “Don Juan deMarco” of the movies (from the same guy who wrote “Creator” and the screenplay for “Bagger Vance”) and whole hosts of thers. Considering hoe common “John” is as a name, we shouldn’t be surprised.
What I wanna know is why there are so many "Sugar Ray"s (Sugar Ray Robinson, Sugar Ray Leonard, etc.) and "James Earl"s (James Earl Ray, James Earl Carter, etc.)
This site says a “Don” is a member of the hidalgo,the lowest degree of Spanish nobility:
http://www.bartleby.com/65/hi/hidalgo.html
Colibri,at the end of “Part II”,when Don Quixote says that he was mad,he says his real name is Alonso Quixano el Bueno.
In chapter one of “Part I” it says
quote
"They will have it his surname was Quixada or
Quesada (for here there is some difference of opinion among the
authors who write on the subject), although from reasonable
conjectures it seems plain that he was called Quexana. "
Several paragraphs later it explains that he takes a new name for himself:
Quote
“Having got a name for his horse so much to his taste, he was anxious
to get one for himself, and he was eight days more pondering over this
point, till at last he made up his mind to call himself “Don Quixote,”
whence, as has been already said, the authors of this veracious
history have inferred that his name must have been beyond a doubt
Quixada, and not Quesada as others would have it. Recollecting,
however, that the valiant Amadis was not content to call himself
curtly Amadis and nothing more, but added the name of his kingdom
and country to make it famous, and called himself Amadis of Gaul,
he, like a good knight, resolved to add on the name of his, and to
style himself Don Quixote of La Mancha, whereby, he considered, he
described accurately his origin and country, and did honour to it in
taking his surname from it.”
Thanks for the clarification, *donkeyoatey. I just checked the introduction for his name - I didn’t have time to read the whole thing! Anyway, it seems that Cervantes himself got the name wrong in the intro. 
Note that in Castenada’s works, the other sorcerers are also referred to as “Don.” IIRC, there’s a Don Gregorio, for example.