Lauren McCann learned a lot from watching her friends struggle freshman year: With grades. With missing a significant other back home. With making new friends.

Why not share her wisdom, thought the University of Pennsylvania senior.

Out came her project, "Dear Penn Freshmen," a website where she and more than 60 upperclassmen wrote advice letters to their first-year selves, sharing what they wish they had known.

"You miss your boyfriend (he won't matter in two years, pinky promise)," wrote Mikaela Gilbert-Lurie, a junior from Los Angeles, whose piece is titled "Don't Transfer."

The portfolio of letters offers a window into life at the high pressure Ivy League university, but also universal lessons that could apply to freshmen just about anywhere.

"Don't be afraid to mess up. It's not going to be perfect," one wrote.

Students revealed battles they had with eating disorders, drinking and disappointing grades. They revealed vulnerabilities.

"Don't be too distraught when you get that C in calculus," McCann wrote.

"Be nice to your liver," wrote a nursing student.

"Maintain your dental hygiene," urged a student, who lamented her college-born cavities.

The site- - drew 10,000 visitors in 24 hours and over 25,000 the first week, said McCann, 22, a rapid-talking senior from East Greenwich, R.I., during an interview Monday at Penn's Huntsman Hall.

She heard from people in Greece, Brazil, Indonesia, and other countries.

"Like, who the heck in Armenia was looking at it, I don't know," she said.

She's also heard from students at Brown, Harvard, Cornell, Georgetown and other schools, wanting to start similar sites.

"Lauren's project is brilliant," said Adam Grant, a Wharton School professor whose organizational behavior class was the launching pad for McCann's project. "It's such a powerful way to help freshmen gain sage advice from upperclassmen who have been in their shoes."

Grant, Wharton's top-rated teacher, called McCann "a superstar student" who is "passionate about learning and helping others."

McCann told Grant she wanted to transfer all the tips she and others had learned while at Penn.

"It's a really competitive environment here," she said, "and it's really easy to buy into that in a very toxic sort of way." Straight-A students in high school can feel like "the dumbest person in the room," she said. Isolation can set in.

Penn in recent years has dealt with a number of student suicides.

"There's nothing more comforting in the world than hearing 'me, too,' " McCann said.

The project was not for a grade or for credit.

"When I find something I'm really excited and really passionate about, I don't mind spending countless hours on it," she said.

McCann invited her classmates to contribute letters and eventually opened it up to upperclassmen across Penn. Many students signed their names and contact information so that freshmen could reach out. Gilbert-Lurie, the student who wrote about not transferring, said she got responses from freshmen locally and around the country.

"It's probably the most rewarding experience I've had in college," said Gilbert-Lurie, knowing she helped others.

The philosophy major advised her younger self not to leave school: "Just hold on for a little bit longer because if you leave now you'll never learn that Penn is the place that will let you soar to heights you never thought possible.

"It's OK to be sad," she advised, adding, "everyone isn't having the time of his or her life."

The messages resonated with Andrew Ravaschiere, 19, a freshman.

"Just hearing people from the other side is very helpful," said Ravaschiere, of New York City.

McCann said she didn't edit the letters, except in one case where the writer suggested freshmen experiment with drugs.

She allowed frank, sometimes foul, language. She dropped an f-bomb herself in reference to a Microsoft interviewer who she said told her, "You wouldn't fit in because you care too much about social good/making the world a better place."

"That's garbage," she wrote, undeterred.

The daughter of a real estate investor and stay-at-home mom, McCann plans a career that marries social good and business.

"I think business can be a really great source for driving good in the world," said McCann, who at 16 spent the summer volunteering in Haiti after an earthquake.

McCann wasn't motivated to do the project by her own freshman experience. It was pretty good.

"I won the friend lottery," she said, noting her roommates are people she met her first week. "I was an exception to the rule."

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