Sen. Mark Kirk hosted the Illinois boy who inspired his own recovery from stroke
Credit: Courtesy Office of Senator Mark Kirk

Like a lot of boys his age, 12-year-old Jackson Cunningham at first didn’t quite get what a big deal attending President Barack Obama’s State of the Union address would be.

The only thing the Illinois boy could think was: No way I’m putting on any suit and tie for this.

“He’s not a suit kind of person,” says Cunningham’s dad, Craig.

So, it was in freshly creased khakis and a brand-new sweater that Cunningham took his seat in the U.S. House chamber Tuesday night as the special guest of his home-state senator, Republican Mark Kirk – two unlikely best buddies who bonded over the exchange of letters in their worst of times and were, now, able to savor a night neither thought they’d live to see.

“Jackson is one of the reasons I’m at the State of the Union today,” says Kirk, who gave the boy the single guest ticket every member of Congress gets for the president’s annual prime-time speech in the House chamber. “He’s my personal hero.”

After the senator, 55, suffered a massive stroke exactly three years ago, on Jan. 21, 2012, Cunningham, who had survived an almost identical stroke one year earlier, wrote to Kirk as part of a speech-therapy exercise. A pen-pal friendship was born – and it grew through some three dozen subsequent letters and several get-togethers, including at the Rehabilitation Institute of Chicago, where they both spent long hours in therapy to regain the speech and muscle control lost to their strokes.

“I saw a boy who reminded me of who I would have been at his age,” Kirk told PEOPLE for a Sept. 2013 story on the pair’s surprising friendship. Each says he was inspired by the other to keep pushing through rigorous – sometimes excruciating – physical therapy.

“Mark is the biggest motivator for Jackson,” says Craig Cunningham. “The senator is the one person Jackson doesn’t want to let down.”

The boy chronicles his remarkable recovery on his Facebook page, Jackson Cunningham – The Story of Me.

The pair compete together in the annual RIC SkyRise Chicago stair climb up Willis Tower, and just last summer raced at the University of Illinois to celebrate Kirk’s hard work regaining the ability to run. And on Tuesday, they shared a dinner of chicken pot pies and shrimp at the U.S. Capitol before finding their seats for Obama’s big speech.

“I’ve never really seen anything like that,” Cunningham tells PEOPLE. Allowed to skip school for the trip from Oakwood, Illinois, Cunningham got all of this week’s homework done in advance and says he’ll be getting back to his seventh-grade classes on Thursday with a new interest in Cuba policy – something he’d never thought about before learning of it from Obama’s speech.

“I’ll probably pay attention more to it now,” he says.

The only souvenir he’ll have to show his classmates: “My ticket to the show.”

And some pretty cool memories of his VIP experience: “I sat two rows away from Mrs. Obama!”

“I still can’t really believe,” says Cunningham, “that, of all the people Mark could pick for his ticket, he picked me.”