Bernard Marx feels out of place because he is physically different from his peers. In the book, it is rumored that someone thought he was a member of the Gamma caste, so they put alcohol in his blood-surrogate, stunting his growth. Regardless of the reason, Bernard possesses the intelligence of an Alpha Plus caste member, but he has the body and appearance of a lower caste member. As a consequence, he is seen as abnormal by his peers and the lower castes. Being ostracized, Bernard retreats into his own world, preferring to be alone or with his only friend, Helmholtz Watson. Furthermore, he criticizes his society and its values, and he feels that he is superior to his peers because he thinks freely and does not, at least in his mind, conform to the conditioning he was subjected to as a child. However, once he returns with John the Savage, and is accepted by his peers, he revels in all the pleasures his society has to offer, completely abandoning his previous attitude towards his society. In the end, he begs Mustapha Mond not to banish him to some remote island, away from the very society he claims to despise when we first meet him.
Helmholtz Watson feels out of place for a different reason. Though he is physically perfect, he is too intelligent. Life for Helmholtz is great, but he is bored. As a writer, he feels that he is capable of great work, but he doesn't know what that work is or how to do it. He is to a degree trapped by his conditioning. When he meets John the Savage and hears Shakespeare for the first time, he begins to see the beauty and potential of poetry. He also begins to realize that pain and suffering, emotions that he has never felt, are necessary to create art. Unlike Bernard, Helmholtz readily accepts his banishment. Given a choice of islands he would like to be sent to, he asks for one with bad weather so he can be a better writer.