Willy has always been desperate for his son to achieve the greatness and recognition of which he himself was not capable. He is driven by the fatherly instinct to see his son attain success, but is also motivated by guilt. Finally, his mental fragility shows us that he needs a positive outlook, however untrue, to help him carry on
Willy is reminded by Bernard in Act II that Biff changed dramatically after visiting Willy in New England-
BERNARD:…I’ve often thought of how strange it was that I knew he’d given up his life. What happened in Boston, Willy?
Willy is very close to burn out when he reaches the restaurant. He needs good news to keep going, however untrue the news is. Willy and Biff argue about whether Biff was really a salesman or a shipping clerk for Bill Oliver. Willy confesses why he needs to believe the lie-
WILLY: I was fired, and I’m looking for a little good news to tell your mother, because the woman has waited and the woman has suffered. The gist of it is that I haven’t got a story left in my head, Biff. So don’t give me a lecture about facts and aspects. I am not interested. Now what’ve you got to say to me?