Craig Williamson was known for his curiosity, his kindness and his childlike belief that, at the end of the day, humanity is actually pretty great.

He was the kind of man who would spend 10 hours in a museum when most people might leave after two. Who made his entire joyful career in a numbers-crunching field called Load Research. Who met his wife over a mutual love of, wait for it … competitive square dancing.

“He definitely had a fascination for trying new things,” said Duncan Williamson, the younger of twin sons. When Duncan pitched the idea of going to France to watch the world-famous 24 Hours of Le Mans car race in 2015, his father turned it into a month-long father-son European adventure that culminated with Craig sitting through a really … really long endurance race he never had the slightest interest in – until his son did. “He sat up with me for all 24 hours – except for two hours of sleep in the rental car,” he said.

After his family, Williamson’s greatest passions were live theater and math, which might sound antithetical but made perfect sense to his son, Phillip. “Because my father believed statistics is as artistic as math can ever be,” he said.

Williamson, the mathematician son of a mathematician, loved to find humor in the symmetry of numbers. His two sons were born on the 22nd. His daughter Charlotte, now 22, on the 11th. “He always said, ‘It’s a good thing there aren’t 33 days in the month, because then your mother would have had three children on the 33rd,’ ” Phillip said with a laugh.

He was, as Phillip put it, a terribly smart person. “And that made him absolutely the worst person to play (the board game) Chronology with,” he said, “because he was so much better at remembering the sequences of historical events than anyone else.”

The man simply loved numbers. He could explain with impossible enthusiasm, for example, the relative merits of mean, median and mode as they applied to judging the Colorado Theatre Guild’s Henry Awards.

But the numbers turned mean themselves on Oct. 5, when Williamson died of a cardiac event at age 60. It was exactly two years and two days to the day after his wife, Marlene, died of brain cancer.

It was a stunning loss for the many communities Williamson touched in his uniquely Colorado life.

Boulder beginnings

Speaking of symmetry: Williamson was born in Minnesota and grew up in Colorado. His wife was born in Colorado and grew up in Minnesota. How they eventually crossed paths is the stuff of legend in local clogging circles.

Craig Bradberg Williamson was born to be an explorer on July 20, 1961, in St. Paul, Minn., one of four siblings born to John and Valerie Williamson. Craig was 5 when his father’s teaching career took him to the University of Colorado Boulder.

Craig graduated from Boulder High School in 1979 and from CU Boulder with degrees in applied mathematics and theater in 1983. In college, he began working summers behind the scenes at the Colorado Shakespeare Festival. He helped with sets, sound, lighting, painting – all of it. He enjoyed climbing on the scaffolding above the Mary Rippon Amphitheatre stage until his wife put a stop to those antics early on in their marriage. “She didn’t want him to be that high in the air,” Charlotte said with a laugh.

By the summer of 1989, Craig had found folk and fellowship in a Boulder group called Calico and Boots, which was, indeed, a competitive square-dancing team. When Craig left the country that summer to visit his parents in Europe, the group was joined by a new Coloradan named Marlene Kay Brenton. She was 5-foot-11 and he was 6-foot-3, so by the time Craig returned, Cupid’s clogs had already made their match: This tall pair was destined to be partners in dancing and in life. They were engaged just seven months after they met and married in 1991. They were joined by the twins in 1994 and by Charlotte in 1999.

Williamson soon became a highly sought consultant in a field almost no one can easily explain. Load Research involves the analysis of data on energy use and demand requirements in any particular area. Suffice it to say, Duncan said: “My father is one of only a handful of people with his level of experience and understanding of his field in the world.” And he loved it almost as much as he loved New Year’s Eve family game nights, online Yahtzee parties, sports and monthly poker nights. Which is to say … a lot. The job allowed him to travel the globe, and in the summers he took the family with him everywhere from Seattle to Saudi Arabia.

Williamson’s career allowed him to be fully focused on his children’s upbringing. Their home was a popular playground for neighborhood kids because everyone knew Craig and Marlene as the fun parents.

Williamson also loved to cook, and he often enlisted the kids to help him whip up his special sauce in little yellow Tupperware containers. “He would hand one to each of us, crank up the Beatles’ “shake it up, baby” song – and we would all jump up and down in the kitchen shaking the crap out of that Tupperware,” Duncan said. (And to clarify, Phillip added: “That special sauce was nothing more than flour and water.”

Craig and Marlene encouraged all of their children’s passions, and never let go of their own. “He never lost his childlike sense of wonder,” Duncan said, “and he tried very hard to make sure we never did, too.”

There was only one household hobby that was not optional – and that was theater.

“In some families, everyone plays pee-wee soccer,” Phillip said. “For us, everybody did theater.”

That meant fully participating in Edison Elementary School’s Shakespeare Club. Craig designed the sets, Marlene built the costumes, and the kindergarten twins were ensemble players in “A Midsummer Night’s Dream.” “We had one line: ‘Quite over-canopied with luscious woodbine,’ ” Duncan said. “And no matter how many … many times we have seen ‘A Midsummer Night’s Dream’ with Dad since then,” Phillip added, “whenever that line comes up, he just has to point it out to us.”

One trait Williamson instilled in each of his children was the responsibility that comes with commitment, said Tammy Franklin, founder of the Curtain Playhouse youth theater school. “He taught them that you have to love the work that comes with doing what you love,” Franklin said. Williamson led by example, adding a master’s of science degree from the University of Colorado Denver that he earned during his first four years of fatherhood.

In his precious spare time, Williamson helped many local theater companies put on their plays – and he was good at it. Williamson was nominated for the Denver Drama Critics Circle Award in 1993 for his scenic design for the Aurora Fox’s “Our Country’s Good.”

But Williamson and his children became inextricably intertwined with the Denver theater community on one fateful night in 2002 when Elisa Cohen, then the editor of the North Denver Tribune, invited Williamson to accompany her to a production of “The Comedy of Errors” at The Bug Theatre.

“Talking over the play afterward, it became very clear that Craig should be the one writing the reviews,” Cohen said. And for the next 14 years, the novice journalist served as the bi-weekly paper’s local theater voice. Years later, Williamson could tell you with quintessential exactness the very date that his first review was published: Feb. 6, 2003. It celebrated what he called “a phenomenal” production of “Cabaret” at the now-defunct Theater on Broadway. And from that date on, he did not stop championing the local theater community until the paper shut down in 2017.

On that day, Williamson posted to Facebook: “Since 2002, I have seen more than 500 live performances, written 375 reviews and articles for the Tribune, judged the Colorado Theatre Guild’s Henry Awards, exposed my children and fortunate friends to a plethora of quality theater, and become deeply involved in the Denver-area theater world.”

As a reviewer, Williamson had a fondness for the little guys. He fully embraced the holistic view that all theater is good theater – meaning he found something to like in everything he saw.

“He took me to 40 shows one year, and afterward he would stay and talk to anyone for as long as there was someone to talk to,” Phillip said. “I would say to him, ‘But dad, this one wasn’t very good,’ and he didn’t care. It didn’t have to be perfect for him to love it.”

One of his favorite companies to cover was Buntport Theater, which for years presented a Saturday afternoon live comic-book series for children called “Trunks.” Charlotte figures her father took her to nearly all of the 100-plus episodes over its eight seasons, ending in 2014. But he took them with him to the company’s mainstage shows as well, because Buntport’s highly imaginative offerings were to Williamson what “The Lion King” is to an 8-year-old: Pure wonder.

“At Buntport, we knew right away that Craig really loved theater,” said ensemble member Erin Rollman. One of Williamson’s favorite shows was called “Tommy Lee Jones Goes to Opera Alone,” and it featured the movie star as a life-size puppet. At one point, the puppet says that art might be the saving grace of our civilization, which Williamson seconded in his review.

“Craig lived like he believed that, too, because he consumed theater at an astounding pace,” Rollman said. “To quote Craig himself: ‘We connect, we laugh, we think, and we are entertained. What more can we ask from theater?’ ”

Theater, Phillip added, was his father’s most important and most fulfilling hobby. “It was his joy,” he said, “and he loved it unconditionally.”

Life takes a turn

The Williamsons were faithful members of the Jefferson Unitarian Church, a diverse and inclusive community in Golden that is “incredibly welcoming,” Phillip said. Williamson walked the talk when Phillip came out as gay during his senior year of high school. “I was met with nothing but unconditional love from both parents,” he said. “My coming out was as far from the horror stories that you can get.”

But life in the Williamson household forever shifted when Marlene was diagnosed with brain cancer – though their parents worked hard to make sure it did not. “Even after my mom was diagnosed, people would come over and hang out at our house because the way mom and dad interacted was silly and funny and light and joyful,” said Charlotte.

And after Marlene’s death, she added: “Dad made sure everything was not going to be terrible because of it.”

It gives Williamson’s children comfort to know that he had struck up a new relationship with Joneila Henselman, a grant coordinator at Pikes Peak Community College, in the last year of his life.

Perhaps the greatest testament to Williamson’s job as a father can be seen in what his children are doing now: Charlotte, 22, is majoring in theater performance at Colorado State University with a minor in American Sign Language. Duncan, 27, is studying film and video in Fargo, N.D. Phillip, 27, is the head equestrian coach at the University of Lynchburg (Va.).

Williamson is also survived by two sisters: Anne Williamson Callanan (Terry) Callanan of Fairport, N.Y., and Dawn Williamson (Wheeling) of Dundee, Ore. He was preceded in death by his parents and brother, Bruce.

A memorial service will be held at 4 p.m. Dec. 11 at Jefferson Unitarian Church, 14350 W. 32nd Ave., in Golden. The service also will be live streamed.