That December, at the national championships in Salt Lake City, he won the 5,000. In February 2013, at the junior world championships, he won the 5,000 and took bronze in the 3,000.
"When he's on the ice, it's almost like he's a man," his dad said. "It's all business and focus. It's like you're watching a professional."
Lehman is easy to spot on the ice not only because he wears the same winter hat his mom bought at a meet years ago. He's also the only one who warms up with a neck warmer draped around his face — during the trials he wore one with the Bears logo — because it keeps the wind out of his mouth.
Lehman's only routine before training — taking naps — is no superstition. It's how he finds order through chaos.
He trains two hours away in Milwaukee four days a week, often leaving school about noon to grab lunch at home. If Lehman's mother can't drive him, he gets a lift from Steve Penland, his former coach.
One weekday he trains off the ice, while Saturdays are often races. Sunday is his day off.
"He has to have one, right?" Marcia Lehman said.
Lehman gets nervous before races. His biggest challenge is being mentally prepared.
"Being mentally tough is definitely something I've been working on, and it has helped a lot," he said. "What the great skaters do is ... if they get tired, they just push themselves a little bit more, as opposed to some people who start off really well and once they get tired, they kind of give up and they think that all hope is lost."
At the Olympic trials, a crowd of 3,000 in suburban Salt Lake City and an NBC broadcast made the event the biggest stage of his young career. He tried to block out the atmosphere.
"Thinking, 'You're on national television,' probably would not have helped," he said, laughing.
The preparation paid off, in part because he was hoping only to qualify for the 5,000.
With three laps to go in the 10,000, Lehman was about four seconds behind Kuck — his training partner and the skater he most admires. Lehman said he noticed Kuck losing steam, and he stayed consistent.
As the final lap began, Lehman pushed ahead. He raised his index finger when he crossed the finish line before the official time was posted.
"It's pretty crazy," he said. "Definitely did not expect it."
Last month, his high school had an assembly wishing him good luck. Then it was off to train on an outdoor track in the mountains of northern Italy in Collabo — where he won his two junior world championship medals — before arriving in Sochi, which has a lower altitude similar to that of Milwaukee.
Should he defy expectations and reach the medal podium, he would become the youngest male speedskater to do so since Alv Gjestvang of Norway in 1956.
He and Klaiber are just hoping for a top-12 finish. This time, the experience is what matters. He is ranked 26th in the world in the 5,000.
Lehman will rely on the skates that helped get him to Sochi. They're no longer in production, but his mother found two pairs in Canada. Lehman also uses Viking blades instead of Maple, the choice of most skaters on the U.S. team, including Shani Davis.
Davis once suggested to Lehman not to change anything with his skates if they felt fine. Now Lehman applies that advice throughout his training.
"I've debated if this is really right for me — and then looking back how much success it has brought me — and it has helped," he said. "So why stop now?"