One of John Key's great political insights was that politicians tend to hold losing positions for much too long, often out of a misguided fear of giving the other side a win.
But as Key demonstrated on everything from class sizes to Working for Families to housing, you're often better to just rip the Band Aid.
The public knows governments don't always get things right, and they appreciate it when their leaders show they are listening.
Voters are much less interested in blind consistency than they are in hearing a policy they didn't like isn't going to happen after all.
Between the swift action on fuel tax cuts earlier in the year, and now this, Ardern has shown she isn't afraid to toss unnecessary things off the boat if it saves political capital that can be better used to help people in other areas.
But there's a more fundamental job for Labour around stopping these types of dramas happening in the first place.
What appears to have happened in this case is that ministers were too focused on the policy minutiae, and not thinking widely enough about the politics. That's something that needs to stop.
Of course, the virtues of a more consistently applied GST regime, while surely of interest to officials at IRD, didn't matter to the public as much as the size of their retirement nest eggs.
Recognising in advance where a proposal is likely to break faith with the public is a core job of politicians. It's why we have elected people running our government rather than professional public servants.
The risk of getting sucked into the group-think of their officials is something Ministers need to work hard to avoid.
It's a bit too easy to spend all day signing off decision papers from your department, chatting to officials in your weekly meetings, making rulings on policy debates between different experts, and forget how much the job of being a Minister is about politics.
As a politician, you work first and foremost for the public, and they expect you to keep close to their priorities, deliver on your promises to them, and continually renew your mandate by convincing them that you are on their side and have the best plan to improve their lives.
If you don't do that well, you don't get to do any of the other bits of the job – the ones that involve helping people and making their lives better.
It's tough work, and having worked in politics I know it's much, much harder than it looks.
It requires submitting to the daily humiliations of the democratic system – the jibes of your opponents, the snarky questions from journalists, the taking of your words out of context, the distortion of your policies by your critics.
But there are large parts of the world where political leaders don't have to worry about such unpleasantness. We all know how that ends.
The job for the Government now will be to refocus, get back on the front foot and remember the political job the public sent them to do.
Hayden Munro was the campaign manager for Labour's successful 2020 election win. He now works in corporate PR for Wellington-based firm Capital Communications and Government Relations.
