(CNN) -- Austin Whitney is walking proof that determination -- combined with creative ingenuity -- can turn a seemingly impossible idea into a reality.
Paralyzed from the waist down since a 2007 drunken driving accident, he had worked hard to graduate on time -- and with honors -- from the University of California at Berkeley.
That was reason enough to celebrate. But nothing compared to how he accepted his diploma on Saturday.
Pressing a button on his walker, Whitney rose to his feet at the commencement ceremony. Then, with the flick of a switch, his legs moved across the stage.
The journey lasted seven steps. Halfway through, he glanced over to the cheering crowd of 15,000 people, who were also on their feet.
"It really was beyond my wildest dreams," Whitney said Sunday night. "I'm still decompressing ... it really was overwhelming."
Whitney was able to move his legs thanks to an "exoskeleton" created by a group of graduate students and Berkeley mechanical engineering professor Homayoon Kazerooni.
"They're absolutely amazing," Whitney said of the engineers. "They're my best friends at the university." He has been working with the team for several months.
The project that helped Whitney take his first steps in years dates back to in 2000,when Kazerooni received a grant from the Defense Advance Research Projects Agency -- a division of the U.S. Department of Defense -- to make an apparatus that would allow people to carry heavy loads for longer periods of time, according to Berkeley's media relations department. The idea was to help people to trek across rugged or remote terrain for longer periods, such as when military medics carry away an injured soldier or when firefighters trudge up stairs with their equipment.
Four years later, the idea culminated with the unveiling of BLEEX -- the Berkeley Lower Extremity Exoskeleton. The contraption, which has a backpack frame, connects to a person's legs and uses its own power source to move them without putting undue stress on the muscles of the human attached to it.
"We've designed this system to be ergonomic, highly maneuverable and technically robust, so the wearer can walk, squat, bend and swing from side to side without noticeable reductions in agility," Kazerooni said in a Berkeley press release at the time.
The professor said he envisioned bigger plans for his exoskeleton -- helping a person who cannot walk be able to.
While Kazerooni kept perfecting his exoskeleton project, Whitney was a star student at St. Margaret's High School in San Juan Capistrano, California. There, he was active in student government, participated in sports and acted in plays.
Whitney graduated from high school in May 2007 with a 4.0 GPA, sporting a bright smile and seemingly brighter future.
But his life changed two months later, on the night of July 21. After having a few drinks with friends, Whitney got behind the wheel of his car and then got in a horrific crash.
His best friend almost died, with doctors forced to remove his spleen and treat a fractured vertebra in his neck, according to a public letter from St. Margaret's released soon after the crash. Whitney suffered a broken back, and his spinal cord was instantly severed -- rendering him a paraplegic.
"I did it to myself," Whitney said. "I was consumed by self-hatred. But I realized I had two choices: I could live in the past and be filled with self pity ... (or) face the adversity in my life, not let this cover my goals and dreams and aspirations."
He chose the latter. Ten days after being released from the hospital, Whitney began classes at University of California at Santa Barbara. He eventually transferred to Berkeley, where he pursued a double major in political science and history.
Whitney plans to attend law school this fall and hopes to work in the entertainment business one day. But first, he'll start working full time at Kazerooni's lab on Monday.
Whitney met the professor last year after a friend from wheelchair basketball told him about Kazerooni's project. Whitney called Kazerooni, who invited him to his lab.
"It was like stepping onto the set of a sci-fi movie, this lab," Whitney said.
As a student, he became an integral part of the research team, which named a specially-designed exoskeleton "Austin" in honor of its first test subject.
Because others in the lab aren't paralyzed, "there's a lot of things they don't anticipate," Whitney said. "Once I test the system, I give them feedback. It's a very active role."
Kazerooni told the UC Berkeley News Center that exoskeletons currently on the market can cost more than $100,000. He said creating more affordable exoskeletons will enable more people to experience such technology.
Whitney said his type of exoskeleton isn't designed to replace the wheelchair, as it doesn't have the same amount of speed, agility and maneuverability.
"But there are so many health and mental benefits to be able to stand," he said. "I can't tell you what it means to walk across that stage and look the chancellor in the eye or be able to hug my mom while standing up -- that's priceless for me."
In addition to continuing his work with the exoskeleton project, Whitney also plans to continue speaking to high school students across the country about drinking and driving. In the past few years, Whitney said, he's reached about 40,000 students.
Now, he'll be able to tell them about graduating from college and redefining the impossible.
"When I stood up and I took the first few steps ... I felt a rush of memories," Whitney said. "Everything from the worst moments of my life -- the car accident, realizing I wouldn't walk again -- and then the best moments of my life -- being accepted to Berkeley -- and realizing, wow, I'm really here. I really was able to graduate in four years and wow, I'm really here walking, doing something I thought was 'impossible.' I'm much more hesitant to use that word ever again."
CNN's Greg Botelho contributed to this report.