"I haven't become calloused," Barack Obama says, "and I would like to think that these letters have something to do with that"

Every evening during his time in the White House, Barack Obama read 10 letters from American citizens — making him the first president to take on such a task. (Upon request, the then-president even corrected a student’s homework!) Now, in a new book — To Obama: With Love, Joy, Anger, and Hope by Jeanne Marie Laskas — Obama gets candid about why he responded to the letters and what they taught him.

“Ten a day is what I figured I could do. It was a small gesture, I thought, at least to resist the bubble,” said Obama, who first started writing back to citizens when he was a senator. “It was a way for me to, every day, remember that what I was doing was not about me. It wasn’t about the Washington calculus. It wasn’t about the political scoreboard. It was about the people who were out there living their lives who were either looking for some help or angry about how I was screwing something up.

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“And I, maybe, didn’t understand when I first started the practice how meaningful it would end up being to me,” he added.

To Obama reveals a range of letters Obama received while president: Some writers were supportive, some wanted to share their life story and request help, while others were written in complete hatred of the president and his policies. Laskas explains that the Office of Presidential Correspondence required “fifty staff members, thirty-six interns, and a rotating roster of three hundred volunteers to keep up with about ten thousand letters and messages every day.” Each day, the staff sorted through these mountains of letters. They gave Obama the 10 best.

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“There have been recurring letters,” Obama told Laskas, “and in that category, I would say, are veterans looking for help, young people with heavy student loan debt trying to figure out whether they qualify for some relief, military personnel or military families who are struggling in some fashion with either a decision or a lack of help from the Department of Defense.”

The former president recalled one of his favorite memories tied to the letters. He said he once met a woman who had written to him, and she greeted him with a “big hug.” She explained that when her husband was serving in the military and suffering from PTSD, she wrote a letter to Obama’s office.

“You had the VA (United States Department of Veterans Affairs) call us directly, and that’s what prompted him to get treatment,” Obama remembered the woman telling him.

“That’s when you’re reminded that there’s something about this office that, when people get a response, they feel that their lives and concerns are important,” Obama said, according to the book. “And that can change in some small way, and maybe in occasionally big ways, how they view their lives.”

Image zoom Barack Obama AP Photo/Manuel Balce Ceneta

While Obama couldn’t personally respond to every letter, he did once take the time to correct a young boy’s homework, upon the student’s request.

“Nice job on the homework,” the president wrote to Kenny Jops. “I caught only two words misspelled on the vocabulary list. Dream big dreams.”

He also responded to letters like the one from Eileen M. Garrish, who wrote, “Are you going to keep even one campaign promise upon which you built your presidency?”

Laskas interviewed multiple letter writers to learn why they wrote to the president and how they felt upon receiving a response from the White House. But it wasn’t just the writers’ lives that were impacted — Obama explained that the letters also impacted policies.

“If there was a letter that particularly moved me, jolted me, saddened me, I got in the habit of asking people to circulate it. So that everyone could take a look at it,” he explained, according to the book. The president would sometimes even write notes on the letters, asking staff how they could make things better.

“Those staff probably didn’t always enjoy getting those notes,” Obama told Laskas. “Sometimes, you know, you’d hear back from the staff, and they’d say, ‘Well, this is why we’re doing it this way.’ And I’d say, ‘Well, that doesn’t make any sense. And let’s try to change the policy.’ ”

Image zoom The Obamas Pete Souza/The White House via Getty

Rebekah Erler explained that she wrote to the president because “Obama struck me as someone who knew what a gallon of milk cost,” she told Laskas. Her letter, which detailed her family’s financial struggle, so affected the president that he invited her to the State of the Union address. Erler’s letter even made an appearance in his speech.

“I want our actions to tell every child in every neighborhood, your life matters,” Obama said in the speech, adding, “I want them to grow up in a country where a young mom can sit down and write a letter to her president with a story that sums up these past six years: ‘It’s amazing what you can bounce back from when you have to… We are a strong, tight-knit family who’s made it through some very, very hard times.’ ”

Beyond helping him better understand the concerns of American citizens, Obama explained that the letters also had an impact on him personally.

“I can tick off the bills and the policies and the accomplishments,” Obama told the author. “But I tell you one of the things I’m proud of the about having been in this office is that I don’t feel like I’ve … lost myself.”