He was a college track athlete, a motivated student at Cal Poly Pomona and never touched alcohol before the age of 27.
But his childhood wasn't easy.
He experienced homelessness at an early age and his parents suffered from alcoholism.
"We lived in parks, we lived in cars, we lived in vans, hotel rooms," said Hamlin.
Hamlin and his two brothers were placed into the foster care system. His mom passed away shortly afterwards.
But Hamlin and his brothers were able to stay together and landed in a foster family that kept them on a bright path.
"The home that we were at in Montclair, the foster parents were really adamant about keeping us on track with our education and keeping us athletic," he said.
Eyewitness News first spoke to Hamlin when he was getting ready to graduate Cal Poly Pomona in 2016.
This week he'll be graduating from USC with a doctorate degree and will become a physical therapist.
He hopes that his story can inspire others in the foster care system as well as his patients.
"It's pretty astonishing to see the look on their face and the amount of respect that they carry for me and knowing that this kid went through a lot, but he's able to provide this amount of care for me," he said.