"I have nothing much else to do."
"I was obliged to retire (from work as a CSIRO scientist) at 65 because that was the policy of the Federal Government," Goodall told SBS.
"My work was plant ecology, I was studying vegetations."
The esteemed academic, who received the Order of Australia at the age of 101, now works at Edith Cowan University in an honorary capacity, fronting up to the office four days a week.
When asked what his life would be like without work, he replied: "Well, I don't know. I think it would be very empty. I should probably continue to work at home. I can do much the same sort of thing at home as I am now doing at the university. But it is better to have a place like that."
Goodall's daughter, Karen, said her father "just assumed that he was going to work". Without his career, he would be lost, she said.
"I don't think that he would survive very long, Ms Goodall-Smith said. "His work is his hobby as well as his passion, his interest and without his work, I don't think that there would be a purpose for him anymore."
The program also touched on the case of Kalgoorlie brothel madam Carmel, who at the age of 80 is working well beyond retirement age.
Carmel, whose brothel Questa Casa was featured in the documentary The Pink House, told SBS she bought it at the age of 55 when she was going through a life crisis.
She works from 7am to 1am, running the business, which she admits is in financial strife.
"I get up every morning at 7. I put the sign out. I do the vacuuming. I do the washing from the night before. Because business has
fallen right away, we do the tours. It is the tours that keep our heads above water. That is the most important business in the house."
Carmel told host Jenny Brockie she could not imagine working at anything else.
"Look, I enjoy and I am always there for the girls. The girls are all somebody else's daughter. When they are in the house with me, they are safe."
Also featured was former Australian Idol judge Mark Holden, who described how had reinvented himself as a barrister in his late 50s after being sacked from the show.
"I started in 1971 at Adelaide University and I eventually signed the Bar roll in 2009. So it was a 38-year journey," he told Insight.
"It was thrust upon me and it was the best thing that ever happened because I probably wouldn't have gone back to the law except for the humiliation of being fired and the big slap on the face," he said.
"I wanted my daughter to see her dad reinvent herself because she knew how much I loved that show and how much I loved doing it. I wanted to right the ship."