The book the Life and Voyages of Christopher Columbus which is highly fictionalized is responsible for many misconceptions of Columbus himself. It paints Columbus as a dissident and paints him to be heroic for his efforts to prove the earth was flat.
Columbus did not discover the Americas on purpose, it was an accident and if he had not discovered someone else would have.
A Conquistadors purpose was to report to the crown and petition for rewards. Their reports or probanza de merito downplayed any involvement from other parties aids the misconceptions that a few hundred Spaniards could conquer the new world and overthrow the likes of the Aztecs. These self written reports glorified the author, yet are very important historical documents, and can give an explanation as to how only a "handful" of men could accomplish conquering a new land.
Cortes and his accomplishments can be explained by the use of the proof of merit documents, he simply painted himself in a favorable manor.
The Spaniards may have been outnumbered by native enemies, but were also outnumbered by their native allies. The Spanish did not conquer the Americas unassisted, "friendly Indians" did more than their fair share of fighting.
Africans either slaves or free men were "invisible warriors" often fighting alongside the Spanish but a rarely mentioned, hence the perception that the Spanish seemed to dominate the battlefield with sheer might.
Many myths were created by what Restall calls the ideology of imperial justification, a system that rewarded the conquistadores. The crown received a share of the spoils and the conquistadores were agents of God which can lead to boasting and pressure to please the crown. The requirements to fulfill a contract or comply with the crown often led to the conquistadores misrepresenting the situation for example Columbus claimed there was plenty of gold and friendly natives in the Americas.
The conquest was incomplete, after the "competition" conquistadores in Mexico were still seeking treasure, living in the cities they destroyed relying on allies. Remote indigenous populations had no interest in colonization.
Six attempts to settle in Florida and the River Plate basin failed. One group resorted to cannibalism.
Attempts to spread Christianity were incomplete until the 16th century.
"Native desolation" the Natives could not whether the Europeans. Native stereotypes included the sentiment natives were unintelligent were unable to learn. The gist was they were seen as having no culture, ingenuous, and immoral.
The Spanish were not seen as Gods. Columbus spread the myth of apotheosis.
Moctezuma has been falsely blamed for the loss of Mexico because he was too afraid to act.