Hekmat Alqus Hanna worked as a general practitioner near Mosul, in northern Iraq, for 17 years before moving to Australia as a humanitarian refugee in 2012.
But when he arrived, he found his medical qualifications were not recognised because of difficulties obtaining proof from a university that has been engulfed by fighting between Iraqi forces and IS militants.
To return to his much-loved career in medicine, the father-of-three has gone back to school.
"My whole life, I was with people and helping people, I love to do that," he said.
Although he’s got several decades on his classmates, Hanna said he gets on well with them.
“They help me a lot, also, because they are engaging me with them and I'm living like I am 17 while I'm 50! So, it's very, very positive for me," he said.
Bankstown Senior College teaches students between Years 10 to 12, and includes an intensive English centre for students newly arrived in Australia.
About four in five students enrolled in Year 12 at the college are over 20 years of age.
Principal Anne Doyle said they have often been through a lot.
"They have many talents, and a lot of them are extremely bright, but they've gone through a lot of trauma, they've gone through a lot of experiences that we here can't even think of," she said.
Alqus Hanna's wife Lora is enrolled in Year 11 and hopes to become a nurse, while their oldest daughter wants to be a dentist.
"I hope the future will be easier for me and for my family," Alqus Hanna said.
"I hope, also, that I will give back to Australia, because I love Australia.
"I love Australia because they gave us the opportunity to start a new life."
Alqus Hanna will sit his first trial HSC exam in August.