It should be remembered that, for Willy, history repeats itself. Willy was abandoned by his father and older brother when he was little:
WILLY (pulling Ben away from her impatiently): Where is Dad? Didn’t you follow him? How did you get started?
BEN: Well, I don’t know how much you remember.
WILLY: Well, I was just a baby, of course, only three or four years old...
BEN: Three years and eleven months.
WILLY: What a memory, Ben!
BEN: I have many enterprises, William, and I have never kept books.
WILLY: I remember I was sitting under the wagon in — was it Nebraska?
BEN: It was South Dakota, and I gave you a bunch of wild flowers.
WILLY: I remember you walking away down some open road.
BEN (laughing): I was going to find Father in Alaska.
WILLY: Where is he?
BEN: At that age I had a very faulty view of geography, William. I discovered after a few days that I was heading due south, so instead of Alaska, I ended up in Alaska.
Willy's father made and sold flutes. He too was a traveling salesman. Thus, that Willy spent so much of his time on the road is not surprising at all. Compared to his father and brother, however, Willy was much more of a family man, absent for long periods of time though he may have been.
His infidelity can not be so easily explained, but it, too, may stem from his early abandonment. As Willy says to Ben:
WILLY (longingly): Can’t you stay a few days? You’re just what I need, Ben, because I — I have a fine position here, but I — well, Dad left when I was such a baby and I never had a chance to talk to him and I still feel — kind of temporary about myself.
What a sad admission to com from a grown man.