Caden's illness
Caden's illness is a key symbol and is referenced repeatedly. Caden suffers from a strange disease that wreaks havoc on his body, causing him a great deal of pain. Overall, Caden's physical pain symbolizes his spiritual and psychological weaknesses.
Caden's play
Caden's play is a key motif in this film and becomes his obsession. He tries to make the play as realistic as possible, to the point where the lines between reality and fiction become blurred. This ultimately represents his inability to deal with his own personal life and to confront reality directly.
Death
Death is referenced repeatedly in the film, making it a key motif. Caden often speaks about the inevitability of death, and how people are unaware of when their own death will take place. At the end of the film, Caden ultimately succumbs to his own death.
Olive's coat
In one scene, Olive is seen wearing a bright green coat. The brightness of her coat contrasts with the otherwise bleak imagery of the film, emphasizing how much she means to Caden.
All the world's a stage
Ultimately, this film can be seen as a "play within a play," and depicts life itself as being a kind of play. This is represented by Caden's play, in which he attempts to mimic life and depict it as realistically as possible. In one line of the play, Caden says that there are millions of people in the world, and "none of those people are extras." Instead, he says that every person is the lead of their own story, which again contributes to the depiction of life as a play.
