And the famously steady military man, go-to problem-solver for governments, and most recently recipient of a knighthood, does not want to be called Sir.

"Angus - that's what I would have insisted when I had that other mouthful before my name, Air Chief Marshall, and people used to struggle with that. So Angus is fine."

In fact, "Angus" is just a nickname, picked up on day one of pilot training at Point Cook, Victoria, in 1970 and stuck like glue every since.

Even his mother came to call the son she named Allan Grant by Angus.

Houston has been bestowed an honour Prime Minister Tony Abbott has said will be reserved for those who have made such outstanding public service they can never truly resume an ordinary life.

So on Monday I asked Houston when he finds those rare moments of normality, what does he like to do?

He laughed.

"Good question. I've found it very hard to escape actually. I'm always being asked to do things, and I've had to say 'no' quite a few times now."

For all the times he's said yes, Houston has been much in the news of late, despite retiring as chief of the Defence Force in 2011.

He led the Australian response to the twin tragedies of MH370 and MH17, and in 2012 then prime minister Julia Gillard asked him to chair a wise-man's panel to find ways of resolving the vexed challenge of asylum seekers arriving by boat.

"What I like to do to relax is I try and have a very disciplinary approach to exercise," Houston said.

"I find the best way to manage a busy life is to have a good level of physical fitness, and also have the advantage of having had a very relaxing hour or so at the start of the day where you go out and bash the body."

Monday morning began with a "sleep in", he said, rising at 6 o'clock for a 9.7 kilometre run. Cycling is another favourite exercise – and the headspace was needed, as it turned out.

The day was spent fielding constant requests for media interviews, not having anticipated the interest in his award and how the pairing with the Queen's husband Prince Philip would spark fresh questions about Australia becoming a republic.

Houston believes another referendum on ties to the monarchy will be held, but hopes only after a long and considered debate.

"I've very comfortable with the system we've got at the moment. It works well for us," he said.

Houston said warm feelings towards Prince William and wife Kate – who even republican Bill Shorten admitted made a "lovely visit" to Australia in April – had renewed public interest in the monarchy.

But Houston said a debate was healthy provided the risks of changing the system of government were properly thought out and did not become divisive.

"I'd always go with what the people of Australia think," he said – and when I suggested this was a politician's answer, he laughed again: "Do you think I've had too much exposure to them in recent times, do you?"

Houston's reserve and calm perspective on the world is greatly valued and he has spoken with officials preparing the government's new Defence white paper to set the strategic direction for Australia.

He worries about miscalculation in the stand-off between China and Japan over the disputed Senkaku/Diaoyu islands but otherwise, "in our region, things are okay", Houston said.

The surprising rise of Islamic State and its ability to attract support is a concern, but Houston believes Iraq is "a little better" than six months ago, while Syria remains dangerously fragile.

During his time in the military Houston sought to lead by example, empower, and work tirelessly for the welfare of those in his charge.

He said there had been 58 operations involving 55,000 individual deployments – including to East Timor and Afghanistan.

"Obviously the most challenging aspect of that was when we lost people," he said - not only soldiers killed, but the injured and those suffering mental anguish.

Another vivid memory was the boat smashed against the rocks at Christmas Island in 2010, killing as many as 50 asylum seekers.

"Stopping the boats was very important, one way or another," Houston said, reflecting on the policy of the present government.

He remains committed to offshore processing of refugee applications, one of the expert panel recommendations in 2012.

But he also said it was best to ensure refugee processing in regions that are the source of strife.

"There are still people who are on the move," he said. "Bring them in from places like Syria, Africa, Afghanistan, Iraq, direct from the source countries, rather than have them come to our part of the world via a perilous boat journey."

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