Michelle Obama is one of the most famous graduates of Princeton University, but the former first lady has largely stayed away from campus since her 1985 graduation.

Even after becoming First Lady, Obama didn't return to Princeton to give any speeches or accept any honorary degrees. She declined to attend any class reunions.

She has hinted in the past that her time at Princeton, where she was one of a few minority undergraduates, was deeply painful. Even her senior thesis was about the difficult time black students had at the Ivy League school.

In "Becoming," her new biography released Tuesday, Obama gives her most extensive account yet of her years in New Jersey.

Among the revelations:

Obama had few white friends at Princeton.

Obama, then known as Michelle LaVaughn Robinson, arrived as a Princeton freshman in 1981 and found the Ivy League campus a scary place.

As a black student from Chicago, she says she didn't realize how much more prepared her classmates would be for college. Many had gone to prep schools, had SAT tutors and arrived at college socially and academically ready for the rigors of Princeton.

Obama found a group of minority friends through the Third World Center, a Princeton activity center for minority students, and ate dinner with them nightly. She rarely socialized with anyone outside the group.

"I didn't in fact have many white friends at all. I realized in retrospect it was as much my fault as anyone's," she writes in "Becoming."

Obama was solidly in the minority. Black students made up less than 9 percent of the freshmen class. Men outnumbered women two to one.

Obama's white roommate moved out. She didn't learn why for 27 years.

Obama was assigned a triple room in Princeton's Pyne hall as a freshman with two white roommates. Halfway through the semester one of the roommates, Cathy, was moved to another room, Obama writes.

It wasn't until the roommate, Catherine Donnelly, and her mother were interviewed by reporters during the 2008 campaign that Obama said she learned the truth.

Donnelly's mother, a school teacher from New Orleans, went to the Princeton housing office and demanded her daughter be moved, she told reporters.

"I said I need to get my daughter's room changed right away," Alice Brown, the mother, told the Boston Globe in 2008. "I called my own mother and she said, 'Take Catherine out of school immediately. Bring her home.' I was very upset about the whole thing."

Brown said in 2008 she came to regret the decision and was considering voting for Barack Obama. Her daughter said she rarely spoke to Michelle Obama after moving out and regretted not trying harder to become friends with her at Princeton.

For Michelle Obama, the incident illustrated how difficult it was to be black at Princeton in the early 1980s, she says in her book.

The future first lady was grateful, in retrospect, that the truth behind her roommate's sudden departure was kept secret.

"I'm happy to say that I had no idea why," Obama writes.

Though she was a top student at Chicago's first magnet high school and her older brother had gone to Princeton on a basketball scholarship, Obama writes she and other minority and low-income students were at a permanent disadvantage at the university.

"It was like stepping onstage at your first piano recital and realizing that you'd never played anything but an instrument with broken keys," she writes.

She says some students arrived at the dorms on the first day in limos with racks of clothes.

Obama would not have applied to Princeton if she'd listened to her guidance counselor at her Chicago high school.

"'I'm not sure,' she said giving me a perfunctory, patronizing smile, 'that you're Princeton material.' Her judgement was as swift as it was dismissive, probably based on a quick-glance calculus involving my grades and test scores," Obama writes.

She ended up getting in, but she was invited by Princeton to a special three-week summer orientation program to close a "preparation gap" for freshman who might need extra time settling into college, she said. It was mostly minority and low-income students.

Obama revealed she was a pot smoker with David, her boyfriend from Chicago as she entered college.

"We went on real dates, going for what we considered upscale dinners at Red Lobster and to the movies," Obama writes. "We fooled around and smoked pot in his car."

Her boyfriend helped drop her off at Princeton, but they broke up as she started her new life in New Jersey.

Obama never joined one of Princeton's eating clubs.

Princeton's fraternity-like eating clubs are one of the centers of social life at the university. They are where the majority of students eat, party and socialize.

Obama said she passed on "bicker," the process of joining one of the clubs. Instead, she stuck with her friends at the university's Third World Club.

"I was happy with the community of black and Latino students I found through the TWC, content to remain at the margins of Princeton's larger social scene. Our group was small but tight," she writes.

Obama said she felt her classmates and some of her professors scrutinizing her and concluding she was only at Princeton because of affirmative action.

Some of her friends experienced blatant racial discrimination at the university, she said.

Her friend, Derrick, remembers white students refusing to yield the sidewalk to him, she writes. Another friend had six friends to her dorm room one night to celebrate her birthday and got called into the dean's office because her white roommate was uncomfortable with "big black guys" in her room.

The racism motivated Obama to work hard, she said.

"If in high school I'd felt as if I were representing my neighborhood, now at Princeton I was representing my race," she wrote.

One of her college roommates prepared her for living with Barack Obama.

Obama eventually moved in with a close friend, Suzanne Alele, a Nigerian-born student who grew up in Jamaica. She was lighthearted, loved parties and was always in pursuit of things that made her happy, Obama writes.

She was also messy, cluttering their dorm room with piles of clothes and other messes. That clashed with Obama's "control freak" personality, she said.

"Years later, I'd fall in love with a guy who, like Suzanne, stored his belongings in heaps and felt no compunction, really ever, to fold his clothes. But I was able to coexist with it, thanks to Suzanne," she writes. "I am still coexisting with that guy to this day."

One of her fondest memories was running through a New Jersey field.

Obama describes herself as a "box checker" who went through life doing what she was supposed to do, rarely straying from the path.

Obama's college boyfriend, Kevin, was a Princeton football player and a free spirit, she said. One spring day he took her driving in his little red compact car.

"He halted alongside a wide field, its high grass stunted and straw-like after the winter but shot through with tiny early-blooming wildflower," Obama writes.

He tells her they are going to run through the field.

"And we do. We run through that field. We dash from one end to the other, waving our arms like little kids, puncturing the silence with cheerful shouts," Obama writes.

The moment has stayed with her throughout her life.

"It's a small moment, insignificant in the end. It's still with me for no reason but the silliness, for how it unpinned me just briefly from the more serious agenda that guided me every day," she writes.

Obama went right from Princeton to Harvard Law School, though she admits she was less interested in the law than getting other people's approval.

"I was applauded just for getting in, even if the truth was I'd somehow squeaked in off the wait list. But I was in. People looked at me as if already I'd made my mark on the world," she wrote.

Though she didn't have much passion for the law, her degree led her to a job at a high-end law firm in Chicago. There, she was asked to mentor a summer associate named Barack Obama.

Kelly Heyboer may be reached at kheyboer@njadvancemedia.com. Follow her on Twitter @KellyHeyboer. Find her at KellyHeyboerReporter on Facebook.