The Government made the mistake of announcing it was blowing $2.3 billion on war planes in the same week as telling nurses the bank was empty. But they all - with the exception of the Haumaha inquiry fluff - seemed less damaging than earlier errors under Ardern. Possibly because the Government wasn't already distracted fighting fires it had itself lit.
Lesson two. Be firm. You're the boss. Act like it. Ardern's got it in her. We all remember the time she got her finger out, pointed it at a TV host and told him off for his mid-century views on pregnancy in the workplace. It was fierce and we loved it.
But that strength hasn't been on display much since then. A head should've rolled when Labour HQ hid the summer camp scandal from Ardern. Possibly Broadcasting Minister Claire Curran should've been punished for the secret active-wear meeting with then RNZ-boss Carol Hirschfeld.
Winston, though, got his stern face on and it was great. For weeks, he refused to go on a TV show that picked a fight with him. He had a go at Australia over the shoddy way they treat our citizens, then he doubled down on it by dissing their copy-cat flag.
Australia deserved the shade. He nailed "stern but empathetic" when he told the nurses that, yes, he valued them but, no, there's no more money. You might not agree with him - and I don't - but he got the message across.
And the final lesson would be to make friends with business. In fact, this should be a priority. Business confidence is so low it's becoming a real worry. It's as low as it was during the global financial crisis.
Some of that's on Labour for frights like the oil and gas announcement. But a lot of it is unreasonable. A lot of it is just business packing a sad because its mates aren't running the show. Still, Ardern's got to turn that around and quick, or it could become a self-fulfilling prophesy.
Again, Winston has arguably made a better fist of looking more pro-business than Ardern has. He's let it be known that he watered down Labour's plans to repeal 90-day trials. It was his lieutenant Shane Jones who dramatically grabbed his face as if he truly felt the oil and gas industry's pain while he helped the Government knee-cap it.
It's no insult to say Ardern could learn from Peters. He is the longest-serving sitting MP. I'd have been surprised if he hadn't done well. Only, it's taken most by surprise just how well.