Britt Cool earned herself the nickname of “fireman” while working with Buffett at his multinational corporation, Berkshire Hathaway, courtesy of her reputation for stepping in and problem-solving at failing companies.

But before she was the Oracle of Omaha’s right hand, she was—like many graduates—simply trying to get a foot in the door.

In 2009 Kansas-born Britt Cool had graduated from Harvard Business School and embarked on a self-driven project: sending swaths of letters to top executives at companies she admired.

Her request was simple: She wanted a meeting. Yet Britt Cool knew this would come with some rejection.

Speaking to CNBC Make It, Britt Cool—who now runs her own private equity fund, Kanbrick—said the risk of a “no” was far outweighed by the opportunities.

The entrepreneur reportedly worth $50 million reasoned: “The risk is pretty low—it’s that someone is going to say no. So why not try?”

Britt Cool said the “vast majority” of letters went unanswered or came back with a rejection.

But this was something the former CEO of Pampered Chef, a Berkshire Hathaway subsidiary based in Chicago, had been prepared for for decades.

Having worked at her family’s farm stand in Manhattan, Kans., since she was young, Britt Cool said she got used to being rebuffed: “It was such a great training ground, because you have to sell your produce, and you have to talk to people.

“You have to ask, and you get rejected a lot,” she said. “I grew a thick skin. I didn’t have any issue with people telling me no.”

The entrepreneur added she went into the meetings with high-profile individuals without an agenda: “I wasn’t doing it because I wanted a job. That’s not why I reached out to people. I was doing it because I wanted to become more thoughtful. In [Berkshire’s] case, it evolved to that.”

Finally getting a yes

Among the refusals were big catches.

Morgan Stanley and Bear Stearns were among those which came back to now 39-year-old Britt Cool with offers of meetings, which Britt Cool believes she won by being “productive,” “proactive,” and “respectful” in her initial approach.

The cofounder of Smart Woman Securities—which provides personal finance and investment education to undergraduate women—said she went into these conversations well prepared and with researched questions, a tactic which eventually landed her a role as a financial assistant at Berkshire Hathaway.

In the history books of entrepreneurial spirit, asking business titans for help isn’t unheard of. Famously Apple cofounder Steve Jobs, age 12, called Hewlett-Packard cofounder Bill Hewlett to request some leftover electronic parts.

Years later Hewlett offered him an internship.

And it’s also not the first time Britt Cool had used letters as a cold approach; in high school she wrote to organizations she wanted to learn about, adding: “I wanted them to send me brochures and pamphlets. A lot of them didn’t respond.”

Going such pains to land face time with key individuals in the business world takes time and effort—a process Britt Cool said reminded her of applying for college.

“I went through two 400-page books and checked every scholarship I qualified for, and then applied for those scholarships,” she said.

“It requires the discipline and the time and the energy to do it. And to invest in that.”