In Arthur Miller's play Death of a Salesman the character of Willy Loman represents the individual quest for the American Dream. To Willy, this dream means to "make it rich" and to make rich fast. However, Willy only feels this way because the people who are his immediate peers have apparently been able to "make it" the way that he would have hoped.
For example, Willy's brother, Ben, makes it big once he leaves to look for his father and, instead, comes out a businessman who is both rich and successful. Similarly, Willy is inspired by the story of a salesman named Dave Singleton who, apparently, becomes rich from his hotel room selling insurance and the story goes that when he died everyone went to his funeral. These two prototypes upon which Willy bases his dreams are atypical, but Willy is too self-absorbed to think twice before embarking in what will become "the wrong dream, all along".
The "Alaska memory" occurs during one of Willy's hallucinations. In it, he remembers how his brother Ben suggests that he and Willy get into business together and move to Alaska. Willy remembers this memory because it is one of those bitter moments when he could have really made it, if he really had wanted to. However, Linda holds him back and tells him that there is no need to embark in such an endeavor, that Willy does not need to be rich, that he is a good provider, and that he is very well-liked already.
Now, let's explore why Linda would do that and why Willy would listen. The marriage of Linda and Willy is the typical enabler/doer relationship. Linda enables Willy's behaviors of grandiosity and ridiculousness by appealing to his ego. In turn, she receives the comfort and security that she thinks she can get out of not risking anything at all.
This is a pure game of walking on eggshells and is caused by both parties', Linda and Willy alike, deeply rooted insecurities. Linda is really a non-entity in her household. She serves as a trampoline for the comings and goings of Willy, and she lacks the adventure and the imagination that Willy has to find ways to live life. In fact, Linda is quite miserable if we really think about it, living always in denial and in oblivion.
Willy is twice as insecure. His ego is tremendously skin-deep because, to him, only the things that are superficial are worth liking such as looks, appearance, and mannerisms. Therefore, when two extremely insecure people are leading a life together, chances are that one will dominate the other but, together, they will end up nowhere. This is the case with Linda, and the reason why she would stop Willy from following his dream. On the other hand, Willy was too scared to take the initiative and he is also to blame for not taking the chance. In the end, he resents this as he continues to remember this chance in his hallucinations. He is, indeed bitter about it. We do not know if this is what eventually starts his last fall, nor if he detested Linda for it. Remember that this is a marriage of superficial emotion. Hence, Willy may very well have also faked his happiness and his contentment with Linda.