A higher-level HSC maths paper might be one of the most dreaded tasks a year 12 student could do but for Ian Carragher, it's just one way he fills the days.
The 66-year-old also enjoys spending his time playing golf, taking photos and doing high school exams to keep his mind sharp.
He's just one of the many over-65s enjoying retirement in Australia, and the number just like him is about to grow exponentially.
