Don Quijote, P.I.

I'm reading Don Quijote for a class I'll be teaching this coming semester, and I am struck by the fact that Don Q is essentially a Private Eye -- this is where the genre comes from. What PI doesn't tilt at windmills? Which isn't a knight errant? Which PI doesn't go out into the world righting wrongs, helping the little guy? Which PI doesn't sometimes get it all very wrong?

The problem with recognizing Don Q as a PI comes from the fact that Cervantes created the prototype as a spoof of itself.