What is clear from the chapters that take place after the shipwreck is that this tragic event forces Pi Patel to grow up in a way that he has never had to do before. Prior to this moment in his life, he has always had other characters to run to and hide behind, such as his parents. The events he narrates in his childhood and in his life before the shipwreck indicate a young man who is trying to find his way in the world and is unsure of his identity and purpose. This uncertainty vanishes when Pi is able to take stock of his situation and faces up to what he has to do in order to survive. Consider Chapter 57, and the direct characterisation that is used to reveal how Pi's present situation actually forces him to accept what has happened to him and to respond to it:
A part of me did not want Richard Parker to die at all, because if he died I would be left alone with despair, a foe even more formidable than a tiger. If I still had the will to live, it was thanks to Richard Parker. He kept me from thinking too much about my family and my tragic circumstances. He pushed me to go on living.
What this reveals about Pi's character and how he has changed is the sudden purpose that he has. Before, as shown through his flirtation with the various religions, Pi lacked this purpose. Now, having to focus so intently on the task of taming Richard Parker, Pi's life is full of purpose, and he recognises that he has no option but to focus on this task, or else give in to despair. Pi, in summary, is forced to grow up in a way that he has never had to do before after the shipwreck.