Much of The Metamorphosis is spent in Gregor's head as he struggles to come to terms with his new form. At times he seems to be able to think abstractly about his condition (as an insect) in ways that sound rational, even if his condition is totally absurd. At other times, it seems that the instincts, drives, and pains of his new body encroach upon his consciousness, influencing his mental life in ways that he can't even begin to understand. Many of the comic moments in Kafka's story result from the inevitable clash between Gregor's pesky body and his beleaguered consciousness.
Gregor's obliviousness to the experience of physical pain is evidence that he continues to have a human consciousness that is distinct from his insect body.
By staging scenes where Gregor momentarily loses his self-consciousness and enjoys being a bug, the story shows how human intelligence may actually create unhappiness and suffering.