I used to have this with Franz Kafka. I couldn't stand his work, because none of it made any sense to me. Then, in college, I came across a book about Kafka's work which casually explained that The Metamorphosis was neither literal nor a metaphor: it was a hallucination that Gregor Samsa was having, caused by a psychotic breakdown, all perfectly according to then-cutting-edge Freudian theory. That perfectly explained * everything* in the story, including the otherwise-inexplicable behavior of his family. — Caliban
I have a very different interpretation. The main theme of the story is an existentialist one: Gregor, by failing to stand up for his own desires and living entirely for the sake of other people, was really always a kind of bug. The transformation just makes everyone else see him for who he really is inside. This is why he doesn't seem to mind it himself (he insists on going to work, early on), and why the "happy ending" is when his family sticks up for their needs, and in the process just lets him die. — Black Humor
To Caliban: You should really see if you can find the 1987 film of "The Metamorphosis" directed by Jim Goddard and starring Tim Roth. Apparently Roth showed no sign of growing extra legs or antennae, and it creeped the bajeezes out of his family. Your discovery made this version make absolute sense.