It's a line from On the Waterfront (1954). The exact quote is: "You don't understand. I coulda had class. I coulda been a contender. I coulda been somebody, instead of a bum, which is what I am,...
Director Francis Ford Coppola (initially) convinced Brando to submit to a "make-up" test, in which Brando did his own makeup.He used cotton balls to simulate the puffed-cheek look.