I remember in one of my Bethel entrants school classes, the instructor commenting on the events that went down in Genesis chapter 3 and commenting that one of the reasons why the serpent was so persuasive was because he "evidently" partook of the tree of the knowledge of good and bad. Because he had taken such a course, he could persuasively convince Eve to do the same.
I can't remember what source material he used to support this assertion. Anyone else heard of this and would like to expound?