The beaming man in the dark suit worked his way with difficulty through a mob of adoring fans, stopping to sign autographs and pose for cellphone snapshots under the protective gaze of a bodyguard.

A rock star? A Hollywood heartthrob? On the contrary, most ordinary Canadians had never heard of David Johnston until recently.

But on Oct. 1, Johnston, 69, the outgoing president of the University of Waterloo, will become Canada's 28th Governor General.

"It'll be the first real job I've ever had, because I never left university," he joked at the recent social, attended by hundreds of enthusiastic students and faculty who wanted to honour him before he left town.

And it's true. The Harvard graduate and lifelong educator began his career as a professor at Queen's University in 1966 before moving on to the University of Toronto, the University of Western Ontario and McGill University, where he served as principal and vice-chancellor.

A Sudbury, Ont., native, Johnston has spent the past 11 years in Waterloo, and two things are clear: It's where his heart will remain, and to members of this southwestern Ontario community -- who insist the rest of Canada will understand before long -- David Johnston is far bigger than Justin Bieber or George Clooney.

"We just can't stop smiling when we talk about him," says Waterloo Mayor Brenda Halloran, who considers Johnston a mentor and a close friend. "He's been one of our best cheerleaders."

Johnston, she says, is funny and personable and has an uncanny ability to remember the most minute details about people.

Halloran also credits him with leading the charge to put Waterloo on the global map.

While the area is known for its pioneering spirit and work ethic, Johnston was able to pull in funding from government and the private sector to transform the university and the region into one of Canada's most innovative high-tech hubs.

"I think David's biggest legacy was taking the University of Waterloo and moving its reputation upwards from being one of Canada's strong research universities to being one of Canada's really outstanding universities," says Kenneth McLaughlin, a Waterloo professor. "It had a good reputation when he came, but what he's done is move it forward dramatically."

Johnston and his family declined interviews. But clearly, he's an over-achiever. He boasts 13 honorary degrees, has written or contributed to dozens of books, articles and conference papers, has published government reports on everything from the Mulroney-Schreiber affair to broadband Internet, has helped write legislation, has moderated federal and provincial election debates and even hosted two 1990s-era public affairs shows. While he specialized in securities law, he understands constitutional issues and should have little trouble if faced with constitutional questions.

Under his tenure at the University of Waterloo, the school's co-op program took on an international focus, encouraging foreign students to study and work in Canada and Canadian students to do the same abroad. Johnston also helped create satellite campuses in the United Arab Emirates, China and Italy.

Meanwhile, construction is nearly complete on the much anticipated Mike and Ophelia Lazaridis Quantum-Nano Centre, expected to be among the few facilities in the world devoted to cutting-edge research in quantum computing and nanotechnology.

Johnston defied critics and, instead of waiting for a big name such as IBM to partner, led the charge to turn the long undeveloped north campus lands into a Research and Technology Park, McLaughlin says. Earlier this month, the school announced the park would be renamed in his honour. While Sybase and Open Text, two of the university's own spinoff companies, were the first tenants, big names such as Google Inc. and Research In Motion have since moved in.

As Johnston begins his tenure at Rideau Hall, any criticism seems to be more over style than substance. Michaëlle Jean, whom he succeeds, is a telegenic, accomplished black woman who touched Canadians with her pleas to help Haiti. Johnston appears, from a distance, to be an establishment white guy.

He's been mildly criticized for his decision to exclude the Airbus scandal from the terms of reference for the 2007 inquiry into former prime minister Brian Mulroney's dealings with businessman Karlheinz Schreiber. A vocal federalist during the turbulent '80s and '90s in Montreal, who co-chaired the Montreal No Committee during the 1995 referendum on independence, he's also garnered criticism from the Quebec sovereignty movement.

But he's known among colleagues for his spirited enthusiasm.

"We used to say that there's no idea that David Johnston did not like," says Amit Chakma, president of the University of Western Ontario and former provost at Waterloo. "It was my job on behalf of the rest of the crew to try to convince David that the idea was great but it was not doable under the circumstances."

Johnston is giving up his nearly half-a-million dollar university paycheque and his spot on four company boards of directors and five not-for-profits, for a non-taxable viceregal salary pegged at just under $130,000 a year. But one thing his friends say he won't give up is Chatterbox Farm.

The sprawling, 100-acre horse-training facility in Heidelberg, a Mennonite community 11 minutes northwest of the University of Waterloo, is the place he and his wife, Sharon, call home.

The couple has reportedly vowed to return at the end of Johnston's mandate."They're everyday people," says Kevin Stemmler, owner of a meat shop down the road.

David and Sharon Johnston, who were high-school sweethearts, have five daughters.

Deborah is a lawyer with Justice Canada; Alex is a lawyer in Ontario Premier Dalton McGuinty's office; Sharon Jr. is a physician and assistant professor of medicine at the University of Ottawa; Jenifer, an economist at Environment Canada; and Catherine (Sam), holds a PhD in education from Harvard University.

Described as independent, fun-loving and bright beyond their years, the girls often helped cater their parents' dinner parties and even crossed paths with the Trudeau boys at their Mont Tremblant retreat. Johnston's daughters hold 21 degrees between them, two are fluent in Mandarin and so far, they've given their parents seven grandchildren.

A lifelong athlete, Johnston still jogs, cycles and skis. At Harvard, he was a star defenceman and captain of the varsity hockey team.

Johnston likes to tell students about the time he was approached by the Detroit Red Wings to play in the NHL but was encouraged by his mother to stick with academics. His on-ice prowess was also immortalized in the 1970 novel Love Story by the late Erich Segal, who once shared a dorm with Johnston and apparently fashioned some of his characters after people he knew from Harvard. In 1988, Johnston was named to the Harvard Sports Hall of Fame. In an article in Waterloo-area Grand Magazine, Sharon describes her husband as a gentleman who taught her French "at arm's distance" during their first date as she was sick with bronchitis, and once signed a note with a very formal "Yours sincerely, David L. Johnston," prompting ribbing from her peers.

While friends say Johnston doesn't talk much about his early years, he was born in Sudbury to Dorothy Stonehouse and Lloyd Johnston, a stay-at-home mom and hardware store owner.

He met Sharon, his wife of 46 years, in high school in Sault Ste. Marie.

In an e-mail exchange, daughter Alex Johnston says her father was very close with Sharon's mother who led a rather extraordinary life. "My mom's mom Joan Downey ... was a divorcee who raised her two daughters alone in Sault Ste. Marie and went back to university to become a social worker when she ended up a single parent in the 1940s," she