Even though he liked the old, man he didn't liked the evil eye of his. But, when he killed the old man he didn't feel sad because he didn't have to see his so called "evil eye." He felt a relief that the evil eye was gone and didn't have to see it. He didn't feel anything after he killed the man over his eye. ("Psychopathic") The narrator had a glib charm because to the policeman, he acted normal towards them. They didn't think the he did anything because he had the glib charm and used it to get away with killing the old man. He acted like nothing was wrong and since he put everything back together the way it was, he was confident that he wouldn't get caught. Since he didn't feel bad killing the man the glib charm was good enough to trick the police. He had convinced them but he went crazy. ("Psychopathic")
The narrator also has parasitic lifestyle. He lives with the old, trying to learn and hopefully one day take over his business/farm. He said he didn't want his money but he still lives with him and not related. The narrator is being supported by this man but the narrator doesn't like the eye. So, he watches him at night and the next day has a lack of motivation.