In Death of a Salesman, the main character, Willy, is a man that is very confused. His grasp on reality has passed him by a long time ago. The only person in his life that really truly cares about him is his wife, who is very nave and thinks that Willy is a confused man. . Willy cannot find his place in the present time; thus he creates an illusion in which he lives. The major theme is about how life challenges can distort your perception, making your reality an illusion. .
The flashbacks in the play make the story come alive. Even though the play takes place in a time period of three days, the flashbacks tell how everything in Willy's life at one time was good. Now, as time changed Willy still thinks that he is living in the past. This provides the viewer with crucial information that helps make sense of the disorder at the Loman household.
Through flashbacks and events in the play, it is apparent that Willy, at least subconsciously, believes his life is now has been terrible. This is the reason he living in the past. He wishes he could have been as great as Uncle Ben, who made his fortunes in the African diamond mines. Willy was having an affair with another woman in Boston and Biff found out about it after his last year in high school. Incidentally, this event probably led to Biff's failure to complete math in summer school, which led to him not graduating high school. By Biff seeing his father having an affair, this really gave him the feeling that life isn't perfect at all, and also, showed his father as a human being and not as a hero as Biff always thought he was. This led Biff to drop most of his ambitions in life and go after dreams that weren't his. This is why Willy always has flashbacks about Biff in high school because it brings him back to the day when his son was popular, smart, and had a great future in front of him; instead, of the present which was worthless and had nothing good going on for himself.