In Greek mythology, Argus the 'All-Seeing' was a giant with a multitude of eyes, enabling him to keep some of them open and watchful at all times. He was tasked with guarding the nymph Io, whom an adulterous Zeus had transformed into a heifer in an attempt to cover his tracks. But he was lulled to sleep and killed by Hermes/Mercury.
The genre of pastoral romance novels, which fancifully detailed the poetic lives and loves of idealised rural figures, had not only equalled but surpassed the popularity of chivalric romance by the time of Don Quixote's publication. It follows then that Quixote's taste would have mirror that of the public, and transferred from one genre to the other, if the cycle weren't broken by his death.
Online edition of Jorge de Montemayor's Diana, translated by Bartholomew Yong (1598)