(CNN) Former President Barack Obama re-emerged into public life on Monday in Chicago and, in the process, offered a potent reminder of what a radical change in direction the country took in the 2016 election.

Obama sat in the middle of a group of young people -- all of whom shared their own personal stories about their involvement in public life and why more people their age didn't follow their lead. He spoke, briefly, at the start of the event about what drew him into community service and politics -- "this community taught me that ordinary people, when working together, can do extraordinary things" -- but spent most of the rest of the event serving as the moderator of the panel.

Obama asked questions here and there to prompt answers from the (nervous) panelists and occasionally would interject his own views, particularly about how the silo-ing of media consumption had created a culture where no one really listens to each other anymore.

But, generally speaking, Obama wasn't actually talking all that much. And, what he did talk about -- the importance of organizing, gerrymandering, the fracturing of the media -- weren't exactly red-meat talking points. It was a professor holding a discussion group with students.

Which, of course, makes sense. Obama's default position is professorial -- to the delight of his allies and the anger of his opponents.

After almost 100 days of Donald Trump, the contrast could not have been more striking.

Trump's first three-plus months in office have been largely defined by a flair for the dramatic and an absolute conviction that the course he is charting -- even if he changes course --- is the right one. There is very little in the way of philosophical conversation about what binds us -- and ails us -- as a country. It's full speed ahead at all times; no BS -- or navel-gazing -- allowed.

That isn't to say one style of leadership is better than the other (although public polling suggests Trump is significantly less popular at this stage of his four-year term than Obama was). It is to say that it's hard for me to imagine that the American public could have chosen two more opposite people to lead the country in consecutive elections.

Some of this has to do with the psychology of the voter. Most people tend to favor a clear change in leadership at the end of one president's eight years in the White House. They react to the qualities they dislike in the current president and seek out a new candidate who seems to embody the opposite of those traits.

So we went from the brilliant but scandal-plagued Bill Clinton to the solid and steady George W. Bush to the young dynamic leader in Obama. And then to to businessman and political outsider Donald Trump.

But this latest change isn't just par for the course. While Bush clearly represented a break from the negative aspects of the Clinton years, he and his predecessor were still on the same political continuum. Both had been governors. Both had spent years cultivating a political operation. Both were, at their root, orthodox politicians.

Trump is not only not an orthodox politician but was elected on his unorthodoxy. Given that, any Trump predecessor would show him as a major departure. But, Obama and Trump share nothing -- not background, not political view, not anything -- in common.

How could the public elect two men in consecutive elections who share so little in their beliefs about what's wrong with the country and how to fix it? I'm not sure. But my guess is ever-increasing political polarization coupled with a barely-voiced truth that many people aren't entirely sure what they want from their government has a lot to do with it.