What is the main theme in the novel, Being with Henry?

The theme of initiation in the face of love and loss is doubly central to Being with Henry, in which Laker loses his mother to another man and then, having found love with Henry, must face the inevitability of Henry's death. Near the book's conclusion, Laker actually articulates that theme when he asks, "Is this what he came to Henry's to learn? That just as soon as you let yourself love someone, you have to lose them?"