The ghost of Patrocles

Patrocles was a dear friend to the legendary warrior Achilles. In the story of Achilles, after Patrocles is slain, Achilles has nightmares about his friend coming to haunt him. The reason that this relates to the course is that of the culture in Greek life as well as confirmation bias. In Greek mythology, the way to the underworld is something that has to be honored, and those who forswear the acts to get there was said to have been haunted by the spirits of the fallen. This was such a predominant thing that after the death of his friend, instead of believing his nightmares about his dead friend were from the grief he assumed he assumed it was his friends ghost coming back to haunt him.