Manuela Munoz Alvarez always enjoys the fresh new beginning of a school year. But the director of Dowling Hall, the largest first-year women's residence at the University of St. Thomas, knows she's in the honeymoon period.

For the first few weeks of school, she said, roommates (many of whom have been placed together by the school or that magical matchmaker, Facebook) tend to report that "Everything is very nice. They'll say, 'I'm good with you borrowing my clothes, or not shutting off the light.' "

By week three or four, she said, "They're saying, 'I'm not OK with any of this!' "

In most cases, students do work things out, of course. And the college roommate experience is a rite of passage that few want to pass up.

But today's freshmen face a particular challenge as they transition from home to dorm life. With American family size down and the number of household bedrooms up, many millennials never have shared a bedroom before. Those who are the children of divorce might have not one, but two, bedrooms to themselves.

And that means potentially surprising additions to their college curriculum: The Equitable Division of Peanut Butter 101, Advanced Neat Freak and Principles of Clothing Swaps, among them.

"This is a big transition," Munoz Alvarez said, noting that 92 percent of first-year students at St. Thomas live on campus. The challenges don't end in their dorm room, either, she said.

"For more and more millennials, sharing a bathroom is a hard transition, too. 'Oh, now I have to walk down the hall and brush my teeth with other people?' "

"Sharing space is one of the biggest challenges that residents will have when they come to college," added Joey Christenson, a resident adviser on the freshman floor at St. John's University in Collegeville, Minn.

Food stealing. Smelly laundry. Having friends over late at night. As the list of grievances grows, so might tensions, anger and passive-aggressive Facebook posts.

"But when we ask, 'Have you talked to [your roommate] about how you feel?' usually the answer is no," Christenson said.

A rocky road

Adjustment jitters aren't surprising. When you consider two teens leaving the nest for the first time, and arriving with differing interests and habits, it's amazing that things go as well as they often do.

The Rev. Hilary Thimmesh has overseen the arrival of students at St. John's "on and off for about five decades."

Some things are predictable, he said, such as nervousness around living away from home. But he's amused by some modern shifts. Once, students packed up their worldly goods in a box or two. "Now," he said with a laugh, "they bring everything they can imagine."

And students' reliance on social media keeps them connected, perhaps too connected, to family and outside friends.

But the two roomies really do need to learn to get along. "In the best-case scenarios, you get great relationships," he said. "Others say, 'It's fine.'

"We do think it's important to learn how to live with somebody else, to share the space," he said.

Now, more than ever.

This reality didn't occur to me until I was attending a parent orientation recently. A representative from university housing looked out over an auditorium filled with parents and asked a simple question:

"How many of your college freshmen shared a bedroom at home?"

Very few hands went up.

Statistics suggest that modern middle-class parents value the idea of every child having his or her own bedroom. Three-bedroom homes have been the most common type of home built, but that is changing, census figures show. Homes with four and five bedrooms are on the rise. That means sharing a room is increasingly another first for many first-year students.

Some schools like to nip potential interpersonal problems in the bud. Kelsey Hansen, who oversaw first-year students at the College of St. Benedict and now works with older students, preferred to get roommates together to talk right away, "before it was a problem, so they were less likely to fall out of the honeymoon phase."

Others, though, welcome a bit of rockiness.

"We've found that we actually need students to bump into each other a little bit," said Susan Stubblefield, associate director for residential life at the University of Minnesota, where nearly 90 percent of first-year students live on campus.

In the past, Stubblefield said, the U's community advisers sat down with each roommate pairing to develop a "roommate success plan" soon after their arrival on campus. Now advisers wait until week three or four to tackle bedtimes, sharing food, hosting guests and other potential sticking points.

With the adviser leading the discussion, Stubblefield said, "it takes the need to confront one's roommate out of it. Later on in the first year, they feel more comfortable advocating for their own needs."

At St. Thomas, Muñoz Alvarez said, advisers hold meetings with each roommate pair at about week three or four, in which they create a "roommate agreement" that's put in place by early October.

Adviser Abby Heller noted that a relationship needs to be "very toxic" before roommates would be separated. "These are relationships where having them compromise would be mentally or physically harmful for one or both of the roommates. It doesn't happen too often."

Still, it's not unusual for advisers to have to get creative. Muñoz Alvarez recalls one pair of young women "who were just different personalities. They met with their R.A., filled out a roommate agreement, and still things weren't working."

Muñoz Alvarez pulled out the True Colors Assessment and used it to talk about different kinds of people.

"Blues," she explained, are feelers, empathizers. "Greens" are deep thinkers. "Oranges" are wild cards with no plans. "Golds" are Type A's who are extremely planful.

These two were a gold and a blue, the former being "direct all the time," and the latter taking everything "very personally and feeling attacked all the time."

Once they understood their personalities better, "they lived together for the rest of the year."

Thimmesh recalls "best buddies from high school" who started rooming together. "After about a month, they couldn't stand each other. I said, 'Hang in there until the end of the semester.' They worked their way through it and were best friends again."

These stories are the best lesson here. Having a college roommate teaches young people interpersonal skills that they can carry forward into the workplace and future intimate relationships.

At the very least, they'll have a great tale or two to tell their friends during summer break.

"I wouldn't recommend that people get singles going into college," said Heller, who shared a room in Dowling last year. "As an R.A. in a single room now, I kind of miss it."

Next week: When twins separate to go to college.

gail.rosenblum@startribune.com 612-673-7350 • Twitter: @grosenblum