Levi spent 21 days in intensive care and only returned to Dannevirke in September.
A battler, Levi has bucked the trend after undergoing a neuropsychological assessment, surprising health professionals with shortest recovery of anyone known in New Zealand.
But it hasn't been easy for Levi or his family, especially parents Jamie and Joanne, who have battled financial and emotional problems which have left them battered, too.
"The emotional and financial toll just rips you apart," Joanne said, wiping away tears.
Last Tuesday Joanne could only sit and watch as her classmates graduated.
She had to give up her studies to support Levi and is now job hunting.
"Levi has had to learn to walk, talk and feed himself and his memory loss has been huge," Joanna said.
"He's had to go right back to basics."
But for Levi's dad, Jamie, progress has meant just one thing. "I've got him to hug now," he said.
Mentor powerMichael, 21, has been employed by ACC to work with Levi since October last year.
Joanna and Jamie said the job he's done has been amazing.
"There's no way Levi would be at the stage he is now without Michael," Jamie said.
"ACC said they wanted to bottle what he had."
Michael has used his sporting background and work as a personal trainer to help focus on Levi's needs.
"He's got the fitness and health of an athlete now, but his memory loss has been huge," Michael said.
Levi left hospital looking like a twig, his mother said.
"He was gaunt, with weakness in his right side as well as a shaking right hand," she said. "Michael and Dannevirke physiotherapist Jane Kilmister have worked really hard."
And while Levi's progress has been astonishing, it's the smaller milestones that have been huge for the Asken family.
"Everything we take for granted was gone, so when Levi achieved something new in his rehabilitation we'd all get excited," Jamie said. "Things like the first day he went for a swim and the first thumbs-up and his first meal in a restaurant. It's those first steps just like a baby takes.
"At first, after the accident, I felt very cheated. Levi was 18 and couldn't do what other 18-year-olds did. Now, although he has some extremely good friends, we still have to be careful and mindful about what he does.
"Other 18-year-olds are going out clubbing, but if Levi goes out on the town he can't drink because it affects his brain and his recovery. He can't go through those 18-year-old rites of passage.
"But at first everyone, including the doctors, told us we wouldn't have this."
Joanne said she has gone through a grieving process since Levi's accident.
"His personality has changed," she said. "There are still some bits of the old Levi, but not much.
"We're just so lucky to have his therapy team of Michael and the physiotherapist and occupational therapist working with him. There are so many young guys out there with brian injuries as a result of accidents, but not the people to work with them."
It hasn't all been plain sailing, with one of the biggest frustrations for Levi, once a top swimmer, being unable to get his breathing sorted because of the lung damage he suffered in the accident.
"He was passionate about his bike racing, too, and was one of the top in the country and now he can never do that again," Jamie said.
Levi was adamant he wanted Michael to work with him. There was no way he wanted a 50 or 60-year-old caregiver, who would play chess and take him to the gym for an hour.
"Michael knew me and I knew he would push me," he said.
And his dad agrees. "Michael drags Levi along with him, even socialising."
The basics It hasn't been easy.
"At first Levi's filter process wasn't working and at times what came out of his mouth wasn't appropriate," Michael said. "Now the improvement has been huge and I've got him setting goals and I've retaught him how to mow lawns and he even helps me fix my car."
For Levi it's been a process of coming to terms with the mental fatigue he suffers from.
"It took a long time but now I can sort myself out and if I'm out with friends I can say: I've got to go home because I'm tired," he said. Today Levi, his family and therapy team are meeting ACC staff to discuss the first steps in getting the 18-year-old back into supportive work.
"First he has to try and get his driver's licence," Joanne said.
With his dad a dairy farmer, Levi would love to get out and help rather than just watch through the window.
"There are lots of little jobs out on the farm, but we need to go through a process to get a side-by-side motorbike for him," dad Jamie said. "It's not just Levi we've got to think about. It's his support person. Levi won't be able to ride a two-wheeler and you can't have two people on a four-wheeler. But it's important for Levi to have a purpose in his day."
However, Levi isn't sitting around feeling angry and blaming other people for the situation he's in, family friend Annette Kendall said.
"You'll never see him feeling sorry for himself," she said. "But we all think this won't happen to us. My son Cam is 15 and after seeing Levi in intensive care and everyone thinking he wasn't going to survive, that's imprinted on Cam's brain now."
But Jamie said one of the most frustrating things for him was that a lot of people who knew Levi saw what happened to him, yet they still ended up doing silly things.
"Young ones think they're bulletproof, but they're not," he said. "You know, you can talk with Levi for an hour and think there's nothing wrong with him and people assume that. But that physical and emotional roller coaster is terrible. If he's had a couple of hard days, on the third he's a zombie."
Specialists believe Levi's brain will be back to 90 per cent of its capacity in five years, but fatigue will always be something he will have to manage.
"Those major problems will always be there for Levi and he'll have to deal with them," his mum said.
The Askens are planning a move to Te Puke in search of a new life for them all and leaving Michael behind will be the hardest thing.
"We've got to find new challenges, a new life and new friends, despite our strong ties to Dannevirke," Jamie said.
