A's transformation
A's daily transformation, in which he inhabits the body of a different person each day, is a powerful symbol of the fluidity of identity. No matter the body they inhabit, A is the same person: kind, intelligent, and caring. In other words, a person's physical appearance may change, but what makes them who they are does not.
The beach
The beach is a pain point for Justin and Rhiannon's relationship. On the day that A inhabits Justin's body, A and Rhiannon (Justin's girlfriend) go to the beach and have a fantastic time. The next day, when A isn't inhabiting Justin's body, Justin and Rhiannon start an argument about their time at the beach. Justin doesn't remember it; Rhiannon wants nothing more than to remember it.
Love and romance
Discussions about love and romance are a recurrent motif in the novel. Rhiannon spends much of the novel exploring her romantic relationship with Justin and, later, A. She discusses those relationships with friends and other people around her, showing how important it is for her.
Reverend Poole
Reverend Poole has the same body-switching ability that A does. However, Poole takes a different approach to their condition, which symbolizes a different perspective on the same challenge (i.e., their body-switching condition). On one hand, A seeks connection and love; however, Poole takes advantage of his unique situation and takes advantage of the people around them.