The fact that Pi was able to survive for close to 2 years is absolutely amazing. But he wouldn't have been able to live that long, if it wasn't for Richard Parker,the fact that Pi lived on this lifeboat with a 400-pound bengal tiger is simply incredible. Pi was able to survive simply by his ability to think about how to create a survival tent and to create tools out the items that he could find in the lifeboat and sea.

Pi created a life raft so that way he could have more freedom,because while he was on the lifeboat he had about 12-15 feet of space because the rest of it was Richard Parker's area. And to increase the size of his space he made the raft. But eventually he started thinking "well if I'm going to share the same area with this tiger, then i may as well show him that I'm the alpha male. Then maybe I'll get some more space." So Pi took the whistle he found in the locker that he found, in an attempt to increase his restriction on the raft and boat. So eventually by doing this enough he train Richard Parker to allow him to stay and move a bit more around the boat without growling as much at Pi for intruding on his already small space.
The only way that Pi had made it so that he could have more space with the whistle trick is that he had remembered while he was at the zoo he had helped his father train these animals and he had lived with them. And while in the zoo the animals felt secure and not as frightened of what was going to happen to them or frightened of the outside world. But once outside demonstrated by all of the animals, they started doing things that they had been born to be.
So it shows us that the more restriction that we have, the better we feel, the less we have, the more insecure we start feeling about actual life, or a life that involves us living otuside of our parents care.