In "The Life of Pi", restriction was very liberating. Being stuck on the life boat in the middle of the ocean with no one around except for Richard Parker was very stressful, but I think the stress of wild tiger, Richard Parker, saved Pi's life. Besides living with this constant threat, having the tiger on the boat with him gave Pi something to take care of, feed, and train. If Pi had been alone for all that time without something besides himself to take care of he might have lost his mind. The restriction of having to be so close to a wild animal for such a long time, actually kept Pi going. By living through the stress, Pi survived to live his life. Richard Parker was Pi's main lifeline.