He goes to his LDS ward in Orem on Sundays. He likes to read and play catch with his two youngest daughters, ages 10 and 12. Lately, he has been hooked on dominoes. Most mornings, he and his 21-year-old son go jogging.
"I'm a pretty boring person," Nielsen concedes.
But that is Nielsen's private self-image. His emerging public persona is anything but boring.
The part-time Brigham Young University philosophy instructor has become the subject of a steady stream of letters to the editor and who knows how many office water-cooler chats since he penned a guest column earlier this month questioning his church's support of a constitutional amendment banning same-sex marriage.
That attention ratcheted up this past week when BYU opted not to rehire Nielsen because his remarks in the June 4 edition of The Salt Lake Tribune publicly opposed leaders of The Church of Jesus Christ of Latter-day Saints on an issue they deem of supreme importance.
Now the spotlight-shy Nielsen is being flooded with even more e-mails. His name is surfacing in even more letters to the editor. And his voice is popping up in radio interviews.
But don't label Nielsen a rebel with a cause.
"I'm not a revolutionary," he says. "I'm a very flawed human being. I'm not a spokesperson for any movement."
Even so, he is speaking out - as a matter of conscience if not convenience.
The 44-year-old father of four not only openly questions LDS leaders on their backing of the marriage amendment, he also criticizes church statements on wedlock.
In addition, he wonders about his church's position on its past denial of priesthood to blacks, its polygamous history, its membership counts and more.
Nielsen, who says he cherishes his church membership, hasn't always been the questioning type.
"I was a very conformist . . . youth," he says.
Reared like many Utah Mormons, Nielsen was born in Salt Lake City but did most of his growing up in Brigham City. Everyone in his immediate family was Mormon - mom, dad, three sisters and two brothers.
He graduated as student-body president from Box Elder High, earned a scholarship to BYU and served an LDS mission to Zurich, Switzerland.
There he labored in one of the highest missionary leadership posts: assistant to the president.
His mind-set was much different then.
"I just took the line that you don't question your priesthood leaders," Nielsen recalls.
Twenty-five years later, Nielsen is doing just the opposite. He believes the foundation of his about-face was laid by an introductory philosophy class he took his last semester at Weber State University.
Having returned home from his mission, Nielsen transferred from BYU to Ogden's Weber State to be closer to his high school sweetheart, Doreen. Within a year, the two married in an LDS temple.
The philosophy class flicked on a switch in Nielsen's brain.
"It opened me up to this idea of the 'world of ideas' that I hadn't ever experienced before," he says.
With that light-bulb moment, poof went Nielsen's plans to attend law school. Instead, he earned a graduate degree in philosophy from Boston College, then returned to Utah and began teaching philosophy at BYU.
He learned the difficulty of supporting a family on a part-time instructor's wages and, after two years, waded into training and leadership consulting. He spent several years in that field, at one point training Fortune 100 companies as a Franklin Covey consultant.
"That's where I began to see that one of the problems with organizations was our concept, our practice of leadership," he says.
A new thought process, a new philosophy, started forming in his head.
His current thoughts are found in The Myth of Leadership, a 2004 book he wrote that advocates leaderless organizations and peer-based management.
The book rests on two premises: Real communication can occur only between equals; and secrecy breeds corruption and abuses of power.
And so it is that the LDS Church's unbending stand against same-sex marriage isn't the only issue that troubles Nielsen.
He wants LDS leaders to be more open about the church's membership numbers, its finances and its history. He wants leaders to more clearly address the church's past - and future - teachings about polygamy. (The church abandoned the practice in 1890.) And he wants LDS temple weddings open to nonmember and non-tithe-paying parents.
His reasons are both moral and personal. One of his sisters left the faith when, in her view, some church teachings didn't mesh with its history. In addition, a parent of his son-in-law wasn't able to attend the young man's temple wedding to Nielsen's daughter.
"I really hope the membership has the privilege to raise these concerns and not be silenced," he says. "I don't want to attack the church. I'm not an enemy of the church. I don't want to hurt the church or destroy anyone's faith. I want to do things to strengthen the church."
Many who have read Nielsen's remarks and replied in writing argue he is weakening the church.
Certainly that is how his superiors at BYU saw it.
"In accordance with the order of the church, we do not consider it our responsibility to correct, contradict or dismiss official pronouncements of the church," wrote department of philosophy Chairman Daniel Graham in a letter informing Nielsen he would not be welcomed back to teach at the school.
E-mails and letters to the editor assert Nielsen knew he ran the risk of losing his teaching job at BYU after his column appeared - a point Nielsen acknowledges.
His detractors also argue Nielsen could hardly expect BYU bosses to continue to employ and pay him after he openly criticized their superiors.
But many more Utahns and others, at least of those who have responded, back the philosopher.
David R. Keller, a philosophy professor at Utah Valley State College, can see Nielsen's reasoning.
"He was motivated through ethical concerns, not to ruffle feathers or to create a situation of animosity," Keller says. "The tone of it was really concerned about the betterment of the human condition."
Keller would like to see Nielsen teaching at UVSC one day. He already has tapped Nielsen as a speaker this fall for the Orem school's Center for the Study of Ethics, which Keller directs.
Nielsen also has agreed to serve on the advisory board for a group of gay Mormons.
Beyond that, Nielsen doesn't know what his future holds.
He believes his life largely will go on as it did before he spoke up and was put down. He plans to keep attending his Orem LDS ward - no disciplinary action has been handed down - doing consulting work and cheering on his daughters at soccer games. Eventually, he hopes to find more teaching opportunities.
He still will drive the family minivan from time to time, read and run with his son. But this much is sure: He won't be riding the bus to BYU.