I have a spotty memory of when I was in class and I remember what I'm asking about was in the Canterbury Tales or a work of Shakespeare's or something else. Something very old and foundational to English.The phrase/analogy of someone being a leaky bucket or a water balloon/barrel who is full of crap and then the speaker says that if they took some water and filled them with it, all of the crap would come out. Something like that, basically that idea I feel like was in one of those works and I am curious about the origin.