Chicago (CNN) Speaking in public for the first time since leaving the White House three months ago, former President Barack Obama on Monday avoided criticizing his successor, disappointing anyone who was hoping for a clash between the ex-president and President Donald Trump.

In a nearly 90-minute forum, Obama laid out lessons he learned as a young community organizer here in Chicago decades ago and vowed to help bring up the next generation of leaders. He did not once mention Trump's name.

The University of Chicago hosted the event, billed by Obama's office as a "conversation on community organizing and civic engagement." The highly anticipated public appearance happened just days ahead of the symbolically significant 100-day mark for Trump -- a milestone that one Obama adviser insisted is "far from" the former president's mind.

In fact, Obama made clear on Monday that he has little interest so far in reemerging as a figure and spokesperson for the Democratic Party, notably declining to comment on issues like health care and foreign policy.

"I'm spending a lot of time thinking about what is the most important thing I can do for my next job?" Obama said onstage. "The single most important thing I can do is to help in any way I can prepare the next generation of leadership, to take up the baton, and to take their own crack at changing the word."

While Obama did not intend to directly confront or take swipes at Trump on Monday, an adviser said he wanted to be forthcoming -- if asked -- about where he stands on specific policy matters, including areas where he and Trump clearly disagree, a source said.

The closest Obama got to wading into a politically charged issue was when he discussed immigration, as he referred to many undocumented workers as simply "families who are looking for a better life for their children."

"It's not like everybody on Ellis Island had all their papers straight," Obama said. "The truth is, the history of our immigration system has always been a little bit haphazard, a little bit loose."

Obama, 55, reflected on the fact that when he came to Chicago more than 30 years ago as a 25-year-old, he was "filled with idealism and absolute certainty that somehow I was going to change the world."

"But I had no idea how," Obama said. "I am the first to acknowledge that I did not set the world on fire. Nor did I transform these communities in any significant way."

He later joked that the famous line from his speech at the Democratic National Convention in 2004 -- that there are not red states or blue states, but that there is rather one united country -- was an "aspirational comment."

Obama also took on several political and cultural developments that he lamented were exacerbating the country's divisions, including gerrymandering, money in politics and the politicization of media.

"The internet in some ways has accelerated this sense of people having entirely separate conversations," Obama said. "If you're liberal, then you're on MSNBC. If you're a conservative, you're on Fox News."

He even shared a warning with young people about their prolific use of social media.

"If you had pictures of everything I'd done in high school, I probably wouldn't have been President of the United States," he said. "I would advise all of you to be a little more circumspect about your selfies and what you take pictures of."

In the final stretch of the 2016 election, Obama actively campaigned for Democratic nominee Hillary Clinton. More than five months after Clinton's loss, Obama is still not interested in taking center stage on politics, an adviser told CNN.

"He's going to be more of an adviser behind the scenes and not necessarily be in the forefront right now," the adviser said. "At a given time, when it's appropriate and necessary, he'll be out there. But not right now."

Obama is also sensitive to creating space for and supporting his former administration officials in their new endeavors, including former Education Secretary Arne Duncan, who is working to mentor young leaders, and former Attorney General Eric Holder, who is focused on redistricting laws across the country.

Monday's event came together because of Obama's desire to speak directly with young people, a source close to the former President said. Three hundred students from universities around the Chicago area were invited to attend.

On Sunday, Obama spoke at a roundtable discussion with young men from Chicago's Create Real Economic Destiny program, which aims to provide job skills and positive connections to at-risk youth. He was invited to participate by Duncan, the program's founder.

"President Obama listened to the young men's stories and shared some of the challenges that he faced growing up," Obama spokesman Kevin Lewis said of Sunday's conversation. "He expressed that he was optimistic about their potential to positively contribute to their communities and support their families because of the services provided in the program."

For the most part, Obama and former first lady Michelle Obama have steered clear of the public spotlight since leaving the White House. The former President has been spotted playing golf and vacationing on a private island in the Caribbean, but his schedule has been kept tightly under wraps.

The Obamas are also busy working on their memoirs after landing a deal with Penguin Random House that could yield them tens of millions of dollars. The couple plans to live in Washington until their younger daughter, Sasha, graduates high school in 2019. Obama is also slated to appear with German Chancellor Angela Merkel in Berlin in late May and is due to accept an award in Boston prior to that.

Obama ended Monday's event on an optimistic note.

"I have to say that there's a reason why I'm always optimistic, even when things look like they're not going the way I want," he said. "And that's because of young people like this."