Being limited and restricted in the Life of Pi is actually helpful to Pi. I think that because Pi had the restriction of first of all being on a small life boat, and  also Richard Parker being restriction it was easier for Pi to create his bounderies.Because he had these restrictions he is able to have an environment that it is easier to wrap his mind around and helps him to be able to concentrate on keeping himself sane. For example he uses Richard Parker as a huge distraction for himself with training R.P and keeping himself a live by fishing and praying and such.