Pi's father, as the owner and manager of a zoo, taught Pi many lessons about the nature of animals. and about human interactions with him. The most memorable is when he leads Pi to the tiger cage and lets him watch as the tigers massacre a goat, tearing it to pieces and eating it. The "lesson" shocks his mother, who protests, saying that they are "just children," but Pi's father did it for his safety; too often, humans make animals out to be cute, harmless things. They aren't, and Pi needed to know that in order to have a healthy respect for the animals, and also an educated wariness around them. This valuable lesson helps Pi to be very careful around Richard Parker, to plan his strategy very carefully, and to not take Richard Parker's potential ferocity for granted.
Another lesson that Pi picks up from his father is the concept of the "Alpha Male," and how only one person can reign supreme in any given territory. Pi uses this knowledge, along with his experience in training animals that he picked up from the zoo, to establish his dominance as the alpha male on the lifeboat. It is this alone that truly saves Pi from becoming tiger food. He lets Richard Parker know, through the use of the whistle, rewards and punishments that it was because of Pi that Richard was able to stay alive, and that he was to stay put in his part of the lifeboat or else. That knowledge truly saves his life, and helps him to keep Richard Parker alive and well through the journey also.
Pi had unique and fortunate background information, lessons and training, mostly from his father and from working at a zoo, which ensured his survival in a very bizarre and difficult situation. I hope that those thoughts helped; good luck!