But this week in the foreign affairs and defence select committee he was only partially well-informed.
He suggested Defence Minister Gerry Brownlee was in a job he did not like and never wanted and that was the reason Mr Brownlee had given the New Zealand Defence Force a low 50% performance rating on the quality of its advice to him.
The score was correct. No-one but Mr Goff had managed to make it to page 83 of the NZDF annual report on which the barely adequate rating had been disclosed.
It must have been a bitter blow to the defence force, which disclosed it had aimed for a 90% rating.
What Mr Goff perhaps did not realise, because he has already enjoyed the privilege, is that every bloke in Parliament who has ever had a toy gun - and half the women, too - wants to be minister of defence.
Mr Brownlee wanted it in 2011, but he was too overburdened with his earthquake recovery workload.
Jonathan Coleman, a longtime favourite of Prime Minister John Key, got it instead.
Mr Brownlee again asked Mr Key for it in 2014 and, such is his standing for his work in Christchurch, that this time he got what he wanted.
A new minister finding his or her way around the culture and peculiarities of any new department is a testing experience at any time.
Mr Brownlee is not easily fobbed off with an incomplete briefing or half the picture. He is acutely sharp. He wants detail. He wants thorough briefings to stay on top of his portfolio which concerns the life and death of soldiers.
Defence provides unique challenges for any minister. Defence sees itself as an arm of the state, not an arm of the government. Its ‘‘independence'' perhaps reached its most absurd heights last term when NZDF invited the United States to military exercises in New Zealand for the first time in more than 20 years without consulting the Government.
It was essential for NZDF and Mr Brownlee to recover from the rough start and by all accounts they have. From the outset, they were thrown into intense and important work on the fight against Islamic State.
Soon after Mr Brownlee got defence, Mr Key signalled that New Zealand was preparing for a non-combat training role with Australia to help to defeat IS in Iraq, and which was finalised as a two-year mission at Camp Taji outside Baghdad.
Mr Brownlee and the Chief of the New Zealand Defence Force, Lieutenant-general Tim Keating, have been at Nato headquarters in Brussels in the past few days with coalition counterparts, including the United States Secretary of Defence, Ash Carter, focused on the military response to IS.
The meeting was buoyed with statistics suggesting that recruitment by IS was dropping and that 40% of the territory it gained in Iraq and Syria had been recaptured.
Saudi Arabia and a sub-coalition of Muslim countries were there, too, before the meeting, talking up the possibility of putting troops on the ground in Syria.
But Russia's intervention in Syria since October last year has changed everything on both the military and political fronts.
If its aim was to insert itself into one of the most complex conflicts the international community is dealing with, it has worked. If its aim was to make the US look less in control of the situation, it has also worked.
No solution could be considered now without Russia's consent.
An awful lot was unknown a year ago, when the New Zealand mission was finalised, especially how well Iraq was going to receive the training mission.
For that reason, a review was instigated virtually from the outset and that is due in the Cabinet next month, half-way through.
Mr Carter created a news flurry at the end of last year when he sent a form letter to all countries already involved in the fight against IS to ask for greater contributions.
The Australians almost summarily dismissed it last month before Malcolm Turnbull's first White House visit as prime minister.
Canada's profile in Iraq under the Stephen Harper government was similar to Australia's in that it was assisting the United States in air strikes against IS in Syria and Iraq.
But Prime Minister Justin Trudeau this week changed that. Fulfilling an election promise, he withdrew Canada's six fighter jets from the coalition.
But, at the same time, he boosted the number of troops in an advise-and-assist role, from about 70 to 200, a move that had not been foreshadowed in the campaign.
Mr Key said consideration of Mr Carter's request to beef up contributions would occur at the same time as ministers looked at the review.
But all the signals suggest New Zealand's response will be the same as Australia's, that is, we are doing more than our share.
The much bigger issue will be whether New Zealand remains in Camp Taji beyond the two-year deployment.
International focus has shifted for now to Syria and possible solutions.
Russia's bombing campaign of Aleppo in Syria has resulted in the surge of tens of thousands of Syrians to the Turkish border.
It claims to be targeting IS, but rebels opposed to the Syrian regime of Bashar al-Assad say they have been targets. The bombing campaign forced a suspension last week of United Nations-led peace talks in Geneva by UN envoy Staffan de Mistura.
That heightened the importance of yesterday's meeting between the US Secretary of State John Kerry and his Russian counterpart Sergei Lavrov in Munich and a political solution.
Russia's offer of a ceasefire to take effect in a week's time was tabled - a major development. It is yet to be seen what conditions it will attach to it or what bombing plans it is preserving for the next week.
Exasperation with Russia was dripping from the comments on Thursday from New Zealand's ambassador on the UN Security Council, Gerard van Bohemen. War on the ground was having a direct impact on the political talks and therefore on the humanitarian situation, he said. Russia was the direct cause of the crisis around Aleppo.
He also suggested countries with influence over Syria, Russia plainly, use their influence to persuade Syria to let go of all the aid it is stopping. It is hard to predict where the next twist in the fight against IS will occur but it is clear why New Zealand is taking such a cautious approach.
Foreign Minister Murray McCully will no doubt brief the Cabinet on Monday on the humanitarian and political tracks.
Mr Brownlee will be back and will no doubt also brief his Cabinet colleagues on the Brussels military meeting.
If Mr Goff wants to be well-informed, perhaps he should ask Mr Brownlee for a briefing, too.
● Audrey Young is political editor of The New Zealand Herald.
