It's still dark outside when Myron Peterson begins clearing wastebaskets, sweeping empty halls, and leaving behind a trail of unexpected art.

Hours before the school day begins at Christian Heritage Academy in Lakeville, he often pauses at the whiteboard as he cleans up a classroom. He grabs a dry-erase marker and quickly transforms part of the board into a winter scene of kids playing pick-up hockey, a portrait of Shakespeare wearing aviator sunglasses, or a sketch of Snoopy and Woodstock.

His drawings are vivid, lively and well-received by both teachers and students, who high-five him in the hall and leave thank-you notes on the door of his janitor's closet. They are also evidence of a crash that upended his life — and left him with a new gift. More than two years after suffering a traumatic brain injury in a car crash, Peterson, 52, has morphed from an average doodler into a prolific, talented artist.

Maybe it was the damage done to his brain, which still causes searing headaches and scrambles his sentences. Or maybe, he thinks, getting pushed so far off track makes you look at everything a bit differently.

"I could see the shading and contrast I'd never seen before," he said, of learning to draw after the crash. "I was always so busy with life."

The old Myron Peterson was a busy guy. He had a demanding job as a facilities manager for two large churches in Shakopee and Lakeville and an active volunteer schedule. He regularly biked 150 miles a week. Big-hearted and warm, he was the go-to guy for anyone who needed something fixed or a shoulder to lean on.

Two days before Thanksgiving in 2016, he was headed to one of the churches to fix a leaky roof. In the falling snow, another driver slammed into a concrete barrier and bounced into Peterson's Toyota Camry.

There was crunching metal and flashing lights. Peterson, blinking and dazed, managed to pull to the side of the highway. He called his wife and told her he'd been in an accident, but that he'd take the back roads and be home soon. Then he began to cry.

"I knew something was wrong," he said. "I've never cried like that."

It took a few days and several doctors to confirm that something was very wrong. The force with which Peterson's head had slammed against his car door had damaged his vision, his memory, his balance and his motor skills. Driving and working were out of the question. His weeks quickly filled up with appointments for doctors, physical therapists, occupational therapists and eye specialists. Motion sickness and debilitating headaches meant hours of lying in the dark in a room with blackout curtains draped across the windows.

Months later, Peterson had worked up the energy to begin applying for part-time jobs. He knew he wasn't up to the management roles he'd had before and was willing to do just about anything. He applied to mow lawns, tend gardens or cook food. He wasn't picky, but the employers were; each time he'd mention that he had a brain injury, a promising lead would go dark. No one was interested in a worker who might be gripped by a crippling headache at any moment, or who'd need to carry a list to remember simple tasks.

"I think he started to lose faith in himself that he could do things," said Peterson's wife, Kay.

Last fall, a friend mentioned that Christian Heritage Academy, a small school that serves students in prekindergarten through eighth grade, was looking for a janitor. This time, Peterson found an interviewer, principal Gail Wolfe, who wasn't hung up on the injury.

Wolfe said she was looking for a part-time janitor who would fit in well with the school's community of students, teachers and parents.

"I knew he had a demeanor about him that could have an impact on our students," she said.

She did not know about Peterson's newfound artistic abilities — and neither did any of the students or teachers — when the sketches first started popping up in classrooms.

For a while, it was a fun mystery. Often, the artwork matched a topic the class was focused on at the moment. Sometimes, it was just playful: a bouquet of flowers, or a cartoon character. What would show up next? Who had a secret talent?

Eventually, Wolfe let her staff in on the secret. Though Peterson was finding work easier with each passing month, he was still in pain.

"It's like if you have two or three glasses of wine, and then you're on a pontoon for four hours, and then you get off, and you have these legs," he said, swaying a bit, to demonstrate. "That's what it's like for me all the time."

Drawing, and more recently, watercolor painting, have become ways for him to set some of that pain aside. At the school, Peterson will spend a few minutes on a sketch before getting back to work. But at home, he can lose himself in his sketches, in which he frequently illustrates his dreams. To keep himself on task, he sets a timer before he pulls out his pencils or paintbrushes, allowing himself an hour before he must snap back to reality.

It could be years before Peterson can again work more than three or four hours a day, or go days without a migraine. His life may never settle back into its old patterns.

But he said he's hopeful, inspired by the family and friends and medical professionals who have helped him. He's thankful for the people who have made a point to look out for him, like the grocery store manager who checks to make sure he's found everything on his list. He's amazed that strangers who learned of his story after a KARE-11 TV news story want to give him a hug, or send him art supplies. (A stranger in Atlanta mailed the school a box containing 52 colors of dry-erase markers after seeing the segment.)

He now has plans to enter an art show and is making his way through a long list of requests from friends and co-workers who want a Myron Peterson original.

There are bad days and good ones, but Peterson finds peace in his forward progress. He's hopeful that other people with brain injuries, struggling in the same lonely, dark places he's been, will also be able to find the inspiration to charge ahead.

"There's never a bad day, as long as you woke up," he said.