Regrets, the retiring Christopher Pyne may have had a few, but one quickly sprang to mind when he was asked whether, looking back, he wished he had done anything differently.

“I probably wouldn’t have told John Howard in 1993 that his time was over, we wouldn’t go back to him,” he said. “That led to some period in the freezer for me.”

It was a typical response from Pyne, 51, who announced his retirement from politics on Saturday, capping a 26-year parliamentary career in which he rose through the Liberal ranks to his current post of defence minister.

Pyne was the youngest person elected to office when he won the Adelaide seat of Sturt in 1993. “I think I was a bit young at 25,” he said on Saturday.

“At the time I thought I knew everything. So I was preselected at 24, of course, so – I have 18-year-olds now, the idea of them going into federal parliament in six years’ time is kind of scary, so I can understand why my peers thought at the time, ‘he is a bit audacious’.”

As it turned out, the Liberals did go back to Howard. And when Australians put him in the Lodge in 1996, Pyne spent a decade on the backbench.

A Republican and member of the moderate faction of the Liberal party, he was eventually made a minister in the dying days of the Coalition government. When Malcolm Turnbull won a leadership spill to become opposition leader in 2008, Pyne was elevated to the shadow cabinet.

In the Howard years, the South Australian was instrumental in establishing the mental health organisation Headspace and under Turnbull’s prime ministership, he secured major submarine and shipbuilding contracts for his home state, which he cited as an achievement on Saturday.

By the time the Coalition swept to victory under Tony Abbott in 2013, Pyne was sworn in as education minister and leader of the house.

He clashed bitterly with student unions as he pursued plans to deregulate university fees, a proposal contained in Abbott’s unpopular 2014 budget.

It was at the height of that debate, when the Senate was set to reject the proposal, that Pyne dubbed himself “the Fixer” in a comical exchange with Sky News host David Speers.

“I’m a fixer, I’ve fixed it,” he said of the legislation. Asked how he had done it, Pyne said all would be revealed in the budget. “I want it to be a surprise for you,” he said wryly.

In 2017, Pyne caused a furore within the Liberal party when an audio recording leaked of him boasting to a meeting of moderates that they were now in the “winner’s circle”. Pyne suggested he had kept the “faith” during the Abbott years, which led the former prime minister to accuse him of disloyalty.

Asked on Saturday who he would miss from the opposition benches, Pyne unsurprisingly named the Labor MP Anthony Albanese, with whom he sparred regularly in parliament and on a morning TV segment of Nine’s Today Show.

Indeed, it may be his lighter moments that Pyne is best known for. He reprised his role as “the fixer” when Karl Stefanovic asked him to change a tyre live on air while Albanese poked fun from the sidelines. On another occasion, he told Albanese with a smirk: “See you next Tuesday.”

When a 2013 episode of Q&A turned to the death of Lou Reed, Pyne admitted being ignorant about the music of a man he called a “heroin addict and transgressive”. “It’s such an ABC discussion,” he said, mockingly, adding that he preferred Tchaikovsky or Abba. Last year, Pyne sang Fernando on The Project.

Pyne will leave parliament alongside some other big names, including his fellow Liberal moderates Julie Bishop and Kelly O’Dwyer, as well as Wayne Swan and Jenny Macklin on the Labor side.

Witty, wicked and as energetic as he is effective @cpyne has been a dear friend and colleague for many years. Together we secured the future of our Australian defence industry - national & economic security. Thank you! We look forward to the next chapter of Mr Pyne’s Adventures. — Malcolm Turnbull (@TurnbullMalcolm) March 1, 2019

On Saturday, Pyne denied that last year’s ousting of Turnbull – whom he recently dubbed his Aslan, referencing to the CS Lewis character – was behind his decision to quit. He said he believed the Coalition would win the next election.

“Being in politics is not a life sentence and I’ve been there for 26 years,” he said.

His next move is to start a business – he trained as a lawyer before standing for parliament.

“Some would say I was pretending to be a lawyer while I was campaigning for politics, and I think there is some truth to that,” he said.

“But I intend to go into the business world and see where that takes me.”