The man in navy blue shuffles into the classroom, aided by a walker, with his wife by his side.

“Well don’t get mad at me,” she says.

“I wasn’t mad at you, I was mad at it,” he says, pointing at a desk obstructing his path. She places a pillow on his chair and he begins to sit, a slow descent into comfort. He sits, momentarily putting off the interview until his breathing steadies.

His name is Robert W. Greene. At 79 years old, he looks as if years of a more than healthy appetite have finally caught up to him, even if his age has not. He has white hair, somewhat sunken eyes and a disposition best described as jolly.

Two years ago his wife, Kathy, used to join him periodically, but now she accompanies him to every class.

At one time Bob Greene was one of the foremost investigative journalists in the country. He was in charge of what later became known as the Arizona Project, an initiative to finish the work of journalist Don Bolles, who was killed by mobsters for pursuing a story that they didn’t want investigated. He was on Richard Nixon’s “enemy” list and he tussled with Senator Joseph McCarthy in hearings. Now he teaches Stony Brook University students on Mondays only, during an early morning three-hour lecture.

Asked about how he deals with the stark difference between his fast-paced days as a reporter and editor and the Stony Brook mornings, he responds good naturedly that when “you get old, the lights start dimming.”

He teaches a class called, “History and Future of the press” and knows that students aren’t always raring to go or at their participatory best at 8:30 in the morning. He joked that he ensures focus from his students by “staring hard at them,” but also by saying hello to everyone.

On this day he starts the class by handing a short 30-minute quiz to students, without getting up. “Read ’em and weep!” he yells. After the quiz he begins quickly with a “topic of the day” to make sure people are awake.

He asks for feedback on Prince Harry, who had been fighting in Afghanistan, and how the media exposed him. Greene explains that this goes back to the classic question of the press and the right to know. The press may think people have a right to know, he says, but they don’t have a need to know.

Greene is at home discussing such questions because he has often been asked to serve as an authority on the rights and wrongs of press coverage. He was part of a four person expert panel on journalism ethics for television’s “60 Minutes” and has often been asked to testify in federal and state courts on journalism ethics.

After the slice of current events, Greene jumps into his lesson — the role of the press as America expanded towards the western frontier. He almost performs his lesson rather than teaching it, his voice venturing to peaks and valleys and his cadence colored with ebbs and flows. He switches his emphasis and juggles his inflections, seemingly entertaining himself while keeping the classes attention. In effect, he’s a one man show. But the show is periodically interrupted by a deep, unsettling cough.

Asked how his health is treating him he immediately deadpans, “crappy.” He adds, “At 79, unless you’re a workout freak you’re going to have problems, but I think I can hold ’em off for a while.”

The frontier topic is part of why Greene does what he does. Here he is teaching about a biased world, where the press levied vile attacks on Native Americans, and where objectivity was nowhere to be found. But he believes it’s just as important to teach this, as it is to teach about the positive things. “I want the students to learn about where we have been at our best and where we have been at our worst. To learn from the best and not imitate the worst,” he said.

Greene speaks in sound bites and seems to revel in the fact.

On the importance of honoring Bolles and doing what he did, he says, “You never saw people killing sports writers or feature writers.” On what students should take away from all of the enemies that he made during his career he said, “Learn how to duck.”

He called anonymous sources “a reporter’s crutch” and lamented the frequency of their use. But he used his harshest tone in condemning a New York Times article about alleged inappropriate relations between John McCain and a female lobbyist. He called it “the worst type of journalism?structurally terrible, insinuative and sleazy.”

Greene has only one wish when his time comes.

“In St. Patrick’s, in Smithtown where my daughter is buried, under her name it says ‘Nurse.’ I want my headstone to say ‘Reporter,” he said. “That’s how I want to be remembered.”