Metamorphosis

"The hero of the story is called Samsa which sounds like a cryptogram for Kafka. Five letters in each word. The S in the word Samsa has the same position as the K in the word Kafka. The A ... "
"It is not a cryptogram" Franz interrupted, "Samsa is not merely Kafka, and nothing else. Metamorphosis is not a confession, it is an indiscretion."
"How is that?"
"It is kind of delicate, and indiscreet, when one tries to talk about the bedbugs in one's own family." Gustav Janouch and Franz Kafka - A conversation in Prague
It is unusual to say the least to open a novel and the first line is about the main character waking up as a large insect. Most authors use symbolism to relate the theme of their work, not Franz Kafka. In Metamorphosis (Die Verwandlung), Kafka uses a literary device that focuses the readers' attention on a single character that symbolizes himself and his life.
The simple, but metaphorically multilayered, story depicts multiple similarities between Kafka's real life and Gregor Samsa, the leading charachter.
Metamorphosis is the story of a young man who, transformed overnight into a giant insect, becomes an object of disgrace to his family, an outsider in his own home, a quintessentially alienated man. A harrowing -- though absurdly comic -- meditation on human feelings of inadequecy, guilt, and isolation.
Metamorphosis is one of the most widely read and influential works of twentieth-century fiction. At the time Kafka wrote Metamorphosis, his own life situation resembled to an astonishing degree Gregor Samsa's just before his metamorphosis. This is revealed by several of his diary entries and especially by a letter Kafka wrote to Max Brod in October 1912, which caused Brod to intervene with Kafka's mother.
Besides his work in the insurance office, which was hateful enough, Kafka also had to take on additional duties in the factory belonging to his father and brother-in-law and all his free writing time was gone, just at a time when "The Trial" had made a breakthrough into his mature literary style and needed all his attention.