How do Rob's previous relationships affect his relationship with Laura in High Fidelity?
In High Fidelity, protagonist Rob is a middle-aged slacker who owns his own record store but has no overarching purpose in life. He has left his first career choice of DJ to pursue both a safe job and his current girlfriend, Laura. At the beginning of the book, Laura breaks up with Rob for another man, leading him to reevaluate his previous relationships.
All of Rob's previous girlfriends, from grade-school on, have either left him, or been left by him. He has no satisfactory answer to the burning question of why, so he visits each of them to discover their reasons.
Ultimately, Rob discovers three things: (1) he has a crippling fear of commitment, (2) he was always oblivious to their needs, and (3) he acted emotionally instead of rationally.
“Maybe we all live life at too high a pitch, those of us who absorb emotional things all day, and as mere consequence we can never feel merely content: we have to be unhappy, or ecstatically, head-over-heels happy, and those states are difficult to achieve within a stable, solid relationship.” -- High Fidelity
As he meets with and is "absolved," in his mind, by each girlfriend in turn, he cycles through stages of denial. First he thinks that fate decides all. Then he thinks that he was rebuffed by frigidity. Then he thinks he won a conquest with no other goal than victory; that he wasn't good enough for a perfect girl; and finally that an average girl wanted something more than himself, the average guy.
Each experience gives him new insight into his part in the breakups. In each case, he cared more for his own feelings than theirs, and felt himself incapable, at an unconscious level, of making the sort of honest commitment that he now craves from Laura.
When Laura's father dies, her uncertain feelings for Rob become resolved in her mind. She takes the initiative in getting Rob off his slacker's throne and back into his first real love, a love he abandoned because of his fear of commitment: disc jockeying at clubs. With her insights, and his new outlook, he finally decides to make the choice he wouldn't before: commit to Laura not as a missing piece of himself or a trophy, but as a whole person with desires and feelings, one who needs his emotional support more than anything else.