Biff Loman is the eldest son of Willy Loman in the play Death of a Salesman. Biff is a man in his thirties, and who has no direction in life. He is still somewhat of a co-dependent child in that, at the time that the play begins, he is staying at his parents' home with his slightly younger brother, and they are still sharing a bedroom like they used to do when they were children.
When Biff was in high school, he hoped to be "the pride and joy" of his father, Willy. However, Willy's own ideals of pride and joy rested unanimously on merely being well-liked, popular, and slick. While Biff continuously followed his father's canon of life, he was unaware that Willy was not living up his own standards: First, Biff found out that his father was cheating on his mother. Second, every one of Willy's and Biff's combined dreams of fame and popularity came crashing down when they both realized that Biff's bad grade in Math would not be changed just by "being well-liked." Hence, Biff suffered the consequences of not being admitted to college, and not playing football anymore.
Willy prolonged the fantasy that Biff was meant to be something quite great. He and Biff were both disappointed. Biff realized that he had acted out his Dad's fantasies and that they were just that: fantasies.
One must wonder if, after Willy's death, Biff changed in any way internally. He must have gone through quite a shock when he realized that his life was a fantasy created by his father. One also wonders whether he will ever be prepared to carry on a life made of self-sacrifice to accept reality. After all, this is the story of a young man who is lost, and had been led by someone who was even more lost than he was.