As Mick Mulvaney takes a seat at the long wooden table in his office in the Eisenhower Executive Office Building, he yells out to an aide about the jobs report just released by payroll processor ADP.

"I can't find the subset for government jobs," the president's budget director says. "Could you find that, please?"

Mulvaney, a former Republican congressman from South Carolina before President Trump appointed him to oversee the Office of Management and Budget, says his office feels like a museum. The Smithsonian sent him a list of approved art, but he doesn't like the options.

"I have to get permission to hang stuff on the walls. So that's why there's nothing here," Mulvaney says.

"It's all crap," he continues. "All I asked for was American maps, cityscapes, famous Southerners. No, none of that. No, they got like a 1970 picture of a grain silo done by a fifth-grader."

When an aide suggests he just put band posters from the Eagles on the wall, Mulvaney jokes about maybe hanging up Dire Straits stuff. "That'd be fantastic. I'd just bring it in and not tell them about it."

To keep his badge out of the photos, Mulvaney removes the lanyard from his neck, turns around and launches it in the air. It lands on his desk on the other side of the room. He cites his favorite one-liner from a former budget director: "No one outside the Beltway's ever heard of OMB, and no one inside the Beltway really knows what we do. And we like it like that."

But Mulvaney, who just oversaw the release of Trump's $4.1 trillion budget proposal for 2018, says he's eyed the office since coming to town with the Tea Party wave of 2010. "As soon as I got to Washington and I found out what this office was I thought that this sounds like the coolest job in Washington."

After Trump won, Mulvaney said, he talked to his friend Texas Rep. Jeb Hensarling, who chairs the House Financial Services Committee. "I said, ‘Does it pass the smell test for me to sort of throw my name in for OMB?' And he's like, ‘It absolutely does because I just gave them your name.'"

Mulvaney said he was attracted to OMB because "if you are a policy wonk and a government junkie, this is the best job ever, and it turned out that it's everything I expected it to be."

Much of the work that went into the president's proposed budget for next year started with the 500 professional OMB staffers, who began building a budget during the Obama administration. "Clearly, there had to be changes made to align with the president's priorities, and that's really what the transition team did," he said. Staffers looked at the president's speeches, public comments and talked to people like White House policy adviser Stephen Miller to turn "those policies into numbers."

Mulvaney, unlike Trump, wanted reforms to entitlement programs, like Social Security and Medicare, in the budget. He had four different hourlong meetings in the Oval Office with the president, where Trump tasked him with balancing the budget without touching these entitlements. "We talked through the various mandatory spending programs and why I thought they needed to be changed, how I thought they could be changed," he said. "And at the end, I gave him a list, and he went down and said yes, yes, yes, no, no, no, yes, yes, no. The nos were Social Security retirement and Medicare."

He's grateful to even make the case to Trump. "It's a policy dream come true to be able to make the arguments directly to the president of the United States, and if I lose, that's great. I'm not the president. He is. And I absolutely respect his final decision."

Trump was especially involved in the top line messaging and the top line numbers during the budget process, including the decision to propose a $54 billion dollar increase for defense, he said. "That was his decision, driven in large part by the fact that it was the exact number to undo the sequester, which was a promise he had made on the campaign trail, and so we sort of back-filled from there."

Mulvaney says he usually is in the office by 7:30 a.m. and works 12 to 14 hours a day. At the entrance of his office is a framed newspaper story with the headline "Trump seeks deep federal cuts." It's signed: "To Mick, Make America Great Again. Donald Trump."

Three days a week, he joins the White House senior staff meeting in the office of Chief of Staff Reince Priebus. Before the budget rollout, he would spend the rest of the day going over the details of the budget. He's also drawn into discussions on healthcare, the debt ceiling and tax reform.

"There is clearly a learning curve when you move into any new job, but I was pleasantly surprised with how much I got," he said.

Mulvaney won praise after several briefings in the White House briefing room, where he promoted the budget and sparred with reporters. "Terrified and scared to death is one way to look at it," he said of those briefings.

A highlight for him was when a reporter asked him about cuts to the National Science Foundation. Mulvaney responded by citing how the foundation spent money on a climate change musical. He asked the reporter if he thought it was a good use of taxpayer money. "And the kid just sat there and didn't know what to say, and I'm like, ‘I'll just take that as a no' because no one says that's a good use of money, which makes you wonder how it got spent in the first place."

He has lost 12 pounds since starting the job. "I lost a bunch of weight, because we've been working all the time. I think I put it all back on. I just forget to eat," he said.

On this day, Mulvaney remembers to eat lunch and invites a reporter to the kitchen outside his office. He pulls out a glass with a presidential seal on it. "I stole this out of the Oval Office," he said, promising to eventually return it. He takes out a loaf of bread and a jar of peanut butter from a cabinet and starts making a sandwich.

Mulvaney, who endorsed Rand Paul in the 2016 primaries, said he considers himself in the libertarian wing of the party. "I've always come from the sort of the school of thought that I don't care what you do in the privacy of your own home."

He said he still advocates, as he did as a congressman, for a balanced budget amendment and term limits for members of Congress, but he hasn't pressed Trump on those issues yet. Yet Mulvaney says he doesn't miss being in Congress and insists he's done with electoral politics. "I'm never going back ... I don't go to fundraisers. I don't read with third-graders. I don't go to ribbon cuttings. I liked all that stuff but, at the end of the day, it doesn't really change the direction of the country."

He laughs about a former Freedom Caucus colleague in the House who recently quipped that Mulvaney seems to be fighting losing battles these days.

"I'm like, yeah, but I'm losing at the very highest level. I used to lose in the Tortilla Coast basement," he said of the famed Capitol Hill meeting spot of House conservatives. "Now I am losing in the Oval Office from time to time, but that's fine."