It would seem that after the writings of Sigmund Freud, modern man has concluded that one's past is also one's present. For, the past is a conduit to the understanding of a character's motivation as well as the backdrop and igniting force of a conflict. In a play that exhibits much of the same Expressionism as those of Tennessee Williams, Arthur Miller also uses the memories from flashbacks as methods of characterization that supply the motivations of the male characters.
(Because this format does not permit too lengthy a discussion, some flashbacks can only be briefly mentioned,)
1. In the exposition of Death of a Salesman, Willy tells his wife that he thinks of the old days more and more. In his first flashback, Willy is vigorous, successful, and confident; his boys idolize him. When Biff tells his father to watch a particular move he will make on the football field, their delight is broken by Bernard's admonition that Biff must study for the statewide Regents exam, and Willy urges Biff to study, yet as Biff continues his urgings, Willy angrily rebuffs Bernard,
WILLY. What're you talking about? With scholarships to three universities they're gonna flunk him?
This question of Willy's is very telling as it reveals the mixed messages that Willy sends to his son as well as indicating Willy's own personal attitudes of over-confidence in present situations without worry about the future, as well as his distorted values (e.g. His high value on popularity makes Willy predict that Biff will be far more successful than the "anemic" Bernard because Biff possesses strength, good looks, and personality).
Indeed, it is because of the salesman's essence of Willy who places such confidence in the illusions attached to success in his business that he believes appearance and strength will bolster Biff in life. Thus, Willy fails to understand the deeper values that Bernard does, and, consequently, fails as a father to Biff.
2. In this flashback, memories converge as Willy first talks with Linda about overcoming their debt because he will "knock'em dead" with his next sales, and then the memory of "the woman" intrudes. Bernard and Charley enter and conflicts are exposed. Charley offers Willy a job, but Willy refuses. He tells Charley that if he had gone with his brother to Alaska, things would be different. Then, Willy's hallucination of talking with Ben begins; Willy admires Ben, who made his fortune on his adventuresome personality over Charley, who simply worked steadfastly. Again, Willy clings to the persona of salesman as the ideal, although his arrogance becomes his nemesis.
All of these scenes develop the personality of Willy along with the effect that he has had upon his sons, whose dishonesty and philandering have been learned from their father.
3. After he is fired, Willy again "talks" with Ben as what is real overwhelms him, and he escapes through memory. Biff as a football play enters and Willy tells him another salesman's belief, “and from there the sky’s the limit, because it’s not what you do, Ben. It’s who you know and the smile on your face.” Bernard rushes in to tell Willy that Biff has failed in math on the Regents.
4. "The Woman" appears again after Biff and Happy leave a restaurant. She is in a black slip and Willy buttons his shirt; just then, Biff is at the door to ask if Willy can get his grade fixed but hears the woman's voice behind a door and is horrified. “You fake! You phony little fake! You fake!” he shouts, disillusioned.