"You want to blame somebody? Blame yourself! (mimicking) 'I'm not even supposed to be here today.' You sound like an asshole! Jesus, nobody twisted your arm to be here. You're here of your own volition. You like to think the weight of the world rests on your shoulder, like this place would fall apart if Dante wasn't here" (Clerks 1994).
When Dante, the protagonist, complains that he was "not even supposed to be here today" he reveals his mistaken self-perception that his presence is essential in his workplace. In reality, like for many service workers, including librarians, it is not. No one is irreplaceable. The final scene from the film reminds the protagonists, and all of us watching, that in a service career if we stopped turning up, if we left for good, we would simply be replaced.