A year ago, as I was visiting Durham, North Carolina, for work, I was asked to be a guest on Mike Krzyzewski’s radio show. So we sat in the conference room adjacent to his office, roles reversed. He asked the questions. I tried to answer.

I figured we’d talk about generic basketball and eventually we did, but first he asked me about my job -- how I got started, what I thought of the evolution of journalism and so forth. I figured he was just being polite until, during a commercial break, we continued the dialogue, him asking even more questions about being a sports writer, me growing more surprised with every question.

Why in the world does Mike Krzyzewski care about my job? Aren’t I, along with my media cohorts, the thorns in his side?

Just this week, associate head coach Jeff Capel explained it.

Duke coach Mike Krzyzewski, shown with LeBron James with Team USA in 2012, isn't stubborn about his philosophies and is always learning. AP Photo/Charles Krupa, File

“We usually have a staff meeting after he tapes his radio show," Capel said. “He has on all sorts of guests, someone in business, a GM or coach from another sport, baseball managers and then he’ll come into our meeting with three pages of notes he’s taken. Sometimes he even plays an excerpt for our team, something he thinks we could apply."

And that’s really the essence of what makes Krzyzewski, after all these years, so fascinating.

The man has won five national championships and two head-coaching Olympic gold medals. Last season, he captured his 1,000th career victory. He is in the Hall of Fame and is a first-team All-Mount Rushmore of college hoops. He could easily sit back and allow people to kiss his ring(s), content in just being Mike Krzyzewski.

And yet he can’t stop, won’t stop and doesn’t want to stop learning.

Krzyzewski is a Ph.D in college basketball with a kindergartner’s thirst for information, his appetite for knowledge nearly insatiable.

“The only thing he hasn’t won is an NBA championship, and that’s only because he never coached in the NBA, but he has a constant desire to learn and improve," Capel said. “He craves it."

The great ones, of course, are always like that – constantly tinkering and never satisfied. It’s more genetic trait than learned skill, this chronic need for self-improvement, but it is also one that can be dulled by success. Complacency has felled more than its share of exceptional people, but if Krzyzewski has a pile of laurels in his office, he has yet to rest on them.

Instead, last summer, when Capel spent his own time involved with USA Basketball, he watched Krzyzewski pull players aside and pick their brains, asking, for example, how slight-of-stature Stephen Curry was able to get his shot off unimpeded. Krzyzewski peppered Tom Thibodeau with so many questions about his defense that, Capel said, by the time Duke’s season started, the Blue Devils were using not only some of the same schemes, but also the same terminology.

“He’s taken what he’s seen in terms of best practices and observes how they train and what they do," Capel said. “They help him, but in turn they fill this constant need of wanting to learn."

Capel played for Duke from 1993 to 1997 and admits that the man who was his coach then and the coach he works alongside today aren’t exactly the same. Mellower isn’t entirely the right word. No doubt, Capel said, Krzyzewski doesn’t live and die with one loss as he did all those years ago, but it’s more than that. He’s adapted – his personality, his style and even at times, his coaching philosophy.

This year, Duke will welcome its second consecutive No. 1 recruiting class to Durham, a group whose way was paved largely because its predecessors left en masse to the NBA. This crew, anchored by Brandon Ingram, could very well do the same. The 2016 crew, which already includes Jayson Tatum, might follow suit.

Duke as a one-and-done "factory?" That reads almost blasphemous for a program and a coach that built side-by-side reputations on the backs of savvy seniors and veteran players.

But times, for better or worse, change. And while Krzyzewski might not love the changes (heck, John Calipari doesn’t even like the one-and-done rule), he has not stubbornly clung to how he would like things to be.

“He very easily could say, ‘This is our way. This is the way we do things,’ and who would argue?” Capel said. “But his willingness to change is probably his greatest strength."

And it’s that combination of improbable inquisitiveness and inventiveness that makes Krzyzewski so fascinating -- a man who has achieved so much, yet wants to be so much more.