How does the theme of isolation arise within the vignettes that focus on Eryk?

Eryk arises each day and chooses "between two" (88) identities. In part because he hates his job working for the ferry service, neither of his two personalities is a joy to encounter, or even to inhabit. The first identity is meek, cowering, and self-hating. When Eryk inhabits this identity, he feels "isolated, lonely, like a child sent to his room looking out the window at his peers" (88) as they play happily. The second personality is arrogant and judgmental, again pushing people away and increasing Eryk's sense of isolation.