PRINCETON, N.J. — Five days after the Peruvian novelist Mario Vargas Llosa won the Nobel Prize in Literature, he walked into a Princeton classroom where 25 students awaited their weekly seminar on the magical realism of the Argentine writer Jorge Luis Borges.

And then, said one astounded undergraduate, he pretended nothing had happened.

“Thank you very, very much,” he said, smiling broadly, according to students who were there and had presented him with a card and a spread of baked goods. “We’ll eat this during the break. But for now, let’s start class.”

Since he won the Nobel on Oct. 7, Mr. Vargas Llosa has been at the center of a whirlwind of attention — “a revolution in my life,” he said in an interview. “It’s really fantastic to experience directly what globalization means,” he said, even though “it has been very comic in some cases.”

He had one offer to invest the prize money — about $1.5 million — in an ice cream company. And someone writing from a remote village, he said, asked him to pay for an operation.

But amid the chaos, this high-flying international literary celebrity has faithfully kept up his duties as a college professor here. Twice a week he wakes up in his Manhattan apartment at 5:30 a.m. to prepare for his classes, one on Borges and the other on creative writing and techniques of the novel, before boarding a train.

“The cultural environment at Princeton is great because there are many writers — Joyce Carol Oates, Michael Wood,” Mr. Vargas Llosa said, adding that he enjoys riding the train back and forth from Manhattan. “It’s very nice. But not if you take the train at 5 or 6 o’clock. It can be a Kafkaesque commute.”

Hairy commutes aside, Mr. Vargas Llosa has settled into a happy New York life with his wife, Patricia. They take an hourlong walk in Central Park each morning, usually around 8. The low-key cafe society of the capitals of Europe and South America is nowhere to be found in New York, he said, so on days he is not on campus, he spends afternoons at theNew York Public Library, which he adores for its ample space and generous natural light.

“Everyone is in a rush in New York, even in restaurants and in cafes,” he said. “You don’t have the serenity. That, I think, is very important in order to read.”

Teaching has been a part of Mr. Vargas Llosa’s life, on and off, since the 1960s, when he had posts at universities in Britain, and later at Harvard, Columbia and Georgetown. He was a visiting lecturer at Princeton in 1992, returning this fall at the invitation of the Program in Latin American Studies.

On Tuesday afternoon he arrived for his usual Borges seminar at Jones Hall, walking into a small carpeted room with five rows of chairs and a wooden desk in the front. As his students quietly filed in, opening laptops and spiral-bound notebooks, Mr. Vargas Llosa, in a salmon-colored shirt and dark-blue tie, his silver hair neatly parted, took his usual seat behind the desk.

Resting his elbows on the desktop, he began an hour of free-floating Borges analysis, describing passages from the stories “The Theologians” and “The Writing of the God,” and delving into a discussion of the point of view of the narrator, the shift from reality to unreality and the themes of isolation, inspiration and imagination. He read the last paragraph of “The Theologians” aloud, a passage in which a character goes to heaven, only to realize that his rival is, metaphorically, his other half.

“It’s an act we can call fantastic,” Mr. Vargas Llosa said, as the students listened intently and scribbled notes. “It’s an act we can call miraculous. Either way, it entirely changes the story we just read.”

The first half of class is typically devoted to his lecture, delivered while seated, with only the occasional glance at his notes.

“It’s hard to really put your finger on it, but there is a gravitas to his way of speaking and presenting ideas,” said Julia Kaplan, 21, of South Brunswick, N.J. “He likes us to deconstruct the stories and really look closely at what is the narrator doing, what tense is the story in, what level of reality is the story at. He’s a wonderful professor.”

Both seminars are taught in Spanish, to classes that include many native speakers who hail from Latin American countries like El Salvador and Mexico.

For his students, holding a seat in Mr. Vargas Llosa’s class has become the equivalent of winning the academic lottery, earning them the sudden envy of friends and fellow students.

“I woke up the day he won and had two e-mails from my parents and friends saying, ‘Your professor’s a Nobel laureate,’ ” said Erick Walsh, 19, a sophomore from El Salvador. “I couldn’t believe it.”