Could you compare Pi in the beginning of the story and Pi after the long journey?

Life of Pi is a coming of age story. Pi narrates the bulk of the story, and as he moves back and forth through time tells the reader about the way his life changed due to an unexpected shipwreck.

Pi is an active boy. He's excitable, an extrovert, loves to have fun, and lives with his family. Our protagonist has no worries and lives in the innocence of his youth protected by his parents. Well, at least until he is separated from his family when their ship sinks. The separation accelerates Pi's growth as a person (or should I say forces it upon him). At this point he is forced to grieve for the loss of his family, become independent, and survive all at the same time. Thus, Pi transitions into adulthood at an unbelievable pace.

Pi's initial feeling is to give up, but his belief in God and miracles sustain him. He passes the time in prayer, and he must often depend upon his wits to deal with the wild animals (Richard Parker included).

Thank you @jill d. Your answer given is much reliable and appreciated.