Much as I enjoy the work of Robert E. Howard, he does occasionally write in such a rush that he makes a mistake.  One such mistake occurs in “The Hour of the Dragon” when he learns the true nature and origin of Xaltotun.

 “Acheron,” he repeated. “Xaltotun of Acheron — man, are you mad? Acheron has been a myth for more centuries than I can remember.”

 Which raises the question, how many centuries does Conan remember? Obviously Howard meant that Acheron had been a myth for so long no one knew how many centuries ago it was known to be real; instead he gives the impression of a centuries-old Conan, who seems a pretty feisty guy for someone that aged.