Someone who has hit an all time low in their life. This is when you need to get counseling or serious syciatric help.
Mr. Carter: "Goofy have you seen your grades lately?"
Goofy: "No Mr. Carter I have not."
Mr. Carter: "Well they're terrible in my book you've hit rock bottom. Do you know the definition of rock bottom?"
Goofy: "No sir I do not."
Mr. Carter: "It means you are Grarbage."