Why is Willy Loman so desperate to portray himself as a successful salesman? --why can't he just admit that he's not a Dave Singleman?in Death of a...

Considering Willy's pseudo-chauvinistic personality it
would be very hard to imagine him adopting any behavior that is humble, nor
passive.

Willy is a man on a mission. Even if his mission
is misguided and founded merely on the few stories he has heard about Dave Singleman, it
is nevertheless his goal in life to be like him.

However,
the worst thing that happens with Willy is that he justifies his ambition by acting as
if he were bigger, more successful, and more well-liked than what he really is. He feels
as if she is "almost there" by acting as if he were already where Dave Singleman once
was. This is why he talks down to people, encourages Biff to do as he pleases, takes in
a mistress, and belittles his wife.

As we know, this is
often the type of defense mechanism that people use to take control of situations. In
Willy's case, he thought that by being petulant ,haughty, and a bully in general, he
would be able to "act the part" of a successful man. Little did he know that, by doing
this, he was less admired and less liked than ever.

Another
thing is that the Lomans are a family with a tendency to deny reality. That, alone, is
the key element that drives the lives of Willy, Biff, Happy, and Linda. They believe in
whatever Willy tells them to believe. Each member of the Loman family enables one
another. Willy creates the dream, and the family enable him by following his lead. Willy
believes that he has the key rules to become a Dave Singleman; he believes that Biff
will make it to college football; he thinks that being well-liked is everything; he
feels that he "runs" some of the major sales areas of his firm. None of these things are
true, but in Willy's imagination. As a result, these ideas rub off on his wife and sons.
In the end, only Biff gets to realize that it was all a fantasy taken way too
far.