Now, he's proving life is possible after a brain injury.
Doug Markgraf, 25, was greeted with applause as he arrived at the Hospital of the University of Pennsylvania on Friday morning. He's coming back to where his journey first started.
Even if he doesn't remember the names or faces of the people who helped him.
It all began after Doug was struck by a pickup truck while on his bike. It was a hit-and-run at 55th and Lancaster that left his bike mangled and Doug with a severe brain injury.
"Anything from the accident I don't remember," he said.
Doug was in a coma for two weeks and, even when he came out of it, things didn't look good.
"Doug was awake and talking to us but really it wasn't Doug," said Dan Markgraf, Doug's father.
"With that severe a head injury we don't always know," said University of Pennsylvania neurosurgeon Dr. Jim Schuster.
"Doctors were saying to me and my family 'We'll be happy if he walks again. I said 'I need to ride my bike,'" said Doug.
With that determination, Doug focused on getting better. He went to Moss Rehab to re-learn how to talk, walk and balance.
Within 11 months he was back on his bike and, this summer, he trekked across the country. He stopped along the way to raise awareness about brain injuries and inspire other patients.
"If I can at least make people who are recovering feel like they are not alone, then I am happy," Doug said.
So far he's gone 3,200 miles. He'll finish his tour in Toms River on Sunday.
"It's hard to put into words how I feel - there's just so much. I'm just so proud," said Jen Markgraf, Doug's mother.
So Doug will finish his more than 3,400 mile bike ride Sunday. On Monday he will be getting his classroom together.
He is a science teacher in South Philadelphia.