The qualification caps a life of learning - Mr Tohill completed his first degree, a bachelor of arts in history, in 1988 when he was executive director of the Race Relations Office in Auckland. He later added honours to his degree, and also completed a graduate diploma in history.
Mr Tohill said he chose Asian studies for the large variety of papers it offered - across history, politics, religion and culture - and because of his connection to the region. He lived in Malaysia, Vietnam and Singapore during his time with the army.
The Castor Bay resident said he found the study rewarding, although he battled with using a computer.
"I did a computer course but I found the terminology confusing. I don't think they'd had one as dumb as me before, so it wasn't a great success," he said.
However, his family, including a granddaughter also studying at Auckland, helped him get through, and he remains very grateful to the university's ever-patient librarians.
"I had a great deal of help from them. Although, in the end, I think they would see me coming and disappear."
Asked if he's going to continue studying, Mr Tohill snuck a glance at his wife, Rose, before saying: "I think I'd be in mortal danger if I did that."
Mrs Tohill replied: "Oh, I can't stop him. He's been like this for 50 years!"
Mr Tohill highly recommends university study to other retirees, saying it did him "a world of good" to be among young minds.
"I was so impressed with the young students in the classes. They were so articulate and intelligent," he said. "It made me think, we've certainly got a future in this country with these sorts of students around. They work damn hard."
The University of Auckland's spring graduation this year includes 2260 students.