Willy's constant movement from the present to the past results in his contradictory nature. Although he fondly remembers Biff as a teenager, he is unable to communicate with Biff in the present. As a result, he praises Biff in one breath, while criticizing him in the next. The cause of Willy's inconsistent behavior is his unbidden memories of a long-ago affair, which he forgets or chooses not to remember until the end of Act II. It is difficult enough for Willy to deal with Howard, his buyers (or lack of buyers), and the everyday reminders that he is not a great salesman like Dave Singleman; however, it is even more insufferable for Willy to accept the idea that he is a failure in his son's eyes.
Prior to the Boston trip, Biff, more than anyone, sincerely believes in Willy's success, potential, and inevitable greatness. Willy is able to achieve the success and notoriety he desires only through Biff, but this changes when Biff learns of the affair. After the Boston trip, Willy tries to regain the success he once had by focusing on memories or events prior to the discovery of the affair. It is not surprising that Willy contradicts himself when speaking in the present about Biff or to him, for although Willy chooses to remember Biff as he used to be, he cannot eradicate the words Biff spoke to him in Boston: "You fake! You phony little fake!"
