Prior to his metamorphosis into a giant bug, Gregor is miserable at his job. He thinks to himself about what a "'grueling'" job he has, and he laments
"the torture of traveling, worrying about changing trains, eating miserable food at all hours, constantly seeing new faces, no relationships that last or get more intimate."
As a traveling salesman, Gregor has been feeling that his position in the company is a lowly one; he is underappreciated and overworked by his boss. Even the ungodly hour at which he must get up every day in order to catch the train and be at work on time, he feels, would make any person "'a complete idiot.'" Worst, perhaps, is that he has no respect for himself either. "He was a tool of the boss, without brains or backbone." In short, Gregor's job makes him feel like one of the lowliest creatures on the planet, and it is, perhaps, this mental metamorphosis that precedes and precipitates his physical change.
His home life isn't much better. Despite his hard work on their behalf, his parents and sister seem to express their appreciation of it about as often as his boss. His mother even seems to think that he's a bit of a loser. She tells the manager,
"That boy has nothing on his mind but the business. It's almost begun to rile me that he never goes out nights. He's been back int he city for eight days now, but every night he's been home."
Gregor pushes himself to work more and more so that he can "make the family forget as quickly as possible the business disaster which had plunged everyone into a state of total despair." When he first begins to earn enough to support the entire family, they are all "delighted" with him, but "Those had been wonderful times, and they had never returned [...]." Despite his continuing support, "no special feeling of warmth went with [the money] any more." Alas, then, before his metamorphosis, Gregor is basically a worker, to all except his sister, and he is routinely unappreciated by everyone but Grete.