In chapter 1, Pi is portrayed as intelligent, somewhat traumatized, nostalgic, and also religious.
That he is intelligent is indicated early in the chapter. He tells us that he "attended the University of Toronto and took a double-major Bachelor's degree." He then says that he was "tops at St. Michael's College four years in a row . . . [and] got every possible student award from the Department of Zoology."
The very first line of chapter 1 is, "My suffering left me sad and gloomy." This line is also set apart as its own paragraph, highlighting its importance. At the end of the next paragraph, Pi says that he wrote his Zoology thesis on the sloth, and one reason he gives for this choice is that the sloth's "demeanour - calm, quiet and introspective - did something to soothe [his] shattered self." The phrase, "my shattered self," in combination with the phrase from the aforementioned quotation, "My suffering," makes it clear early on that Pi has survived some kind of traumatizing event.
Later in chapter 1, Pi also says, "When you've suffered a great deal in life, each additional pain is both unbearable and trifling." The repetition of the word "suffering" in this chapter, alongside words like "shattered" and "unbearable," alludes to the degree of the trauma that Pi has suffered. The reader can assume, at this point, that Pi's suffering will be explained in the subsequent chapters.
In chapter 1, Pi is also characterized as nostalgic for India. He says that, although he loves Canada, he misses:
the heat of India, the food, the house lizards on the walls, the musicals on the silver screen, the cows wandering the streets, the crows cawing, even the talk of cricket matches.
The listing in this quotation emphasizes how much Pi misses India.
Pi is also in this chapter presented as religious. After the first reference to his "suffering," he tells us that "the steady, mindful practice of religion slowly wrought [him] back to life." Later in the chapter, he also refers to some of his fellow students as "muddled agnostics who didn't know which way was up." The implication here is that Pi is somewhat dismissive of people who don't definitively believe in the existence of God.