Banquo, it wouldn't have aided his recovery any to be told. After all, wouldn't he logically just say, "No, it was a chicken"? That's how the process works. That's why there's the popular image of a therapist just saying, "Tell me how you feel about that." The therapist has to know how you feel about things, and the more they get you talking, the more they get you thinking about how you feel and what happened. Just telling someone what their problem really is wouldn't solve anything.
"Now everyone was giving her that kind of look UFOlogists get when they suddenly say, 'Hey, if you shade your eyes you can see it is just a flock of geese after all.'"
"You can't erase icing."
"I can't believe it doesn't work! I found it on the internet, man!"