Someone had brought a bathtub chain. It was all on: Māori v Pakeha.
We were about 8 or 9.
The Māori v Pakeha delineation that had been useful for picking lunchtime rugby or soccer teams had now somehow been applied to a new sport: a racial scrap.
Maybe it spilled over from one of our lunchtime to-dos.
This was a race war in the late 1970s in one of the country's most progressive schools.
We had open-plan "pods" - not classrooms. And no desks. Our work was carried around in plastic "tote trays".
Back to the race war.
The puff went out of our chests when teachers got wind of the scrap, and told us to pull our young heads in. The bathtub chain vanished, the tension went down the gurgler and we were all good mates again.
A few years later, I chased a tennis ball across a cold windy, wintry block of intermediate school asphalt and crossed a boundary.
The boys from Charlie St were in the middle of a game. I had walked across their court. "P**s off you white maggot".
My mouth sometimes operates faster than my brain. "P**s off you brown maggot".
I ran back to my game, and the bell went. Game over.
Until lunchtime, when the boys from Charlie St gathered outside my class.
"What's going on?" demanded my teacher.
There was a touch of the military about James Cope. Impeccable Brylcreemed hair, walk shorts, socks, garters. He wore those 1970s heavy cotton shirts with the lapels.
The colours weren't subtle - when he was on lunchtime patrol, you couldn't miss him.
And he spoke with that beautiful sound you get, when someone fluent in te reo speaker rolls their Rs, all their Rs, all the time.
It turned out I was going to get my head smashed in, for calling one of the leaders of the Boys From Charlie St gang a brown maggot.
Mr Cope was having none of it. Both parties got a stern "don't be stupid!" dressing down. There might have even mention of the strap.
We were all good mates again.
Fast forward to our pristine little country that over the past few decades has perpetuated a global view externally, that we all get along, that we are clean and green, the land of opportunity etc etc. Mainly because many of us believed it.
We need to take a good, long, hard look in the mirror.
It has taken one of the worst hate crimes carried out by an individual that the world has seen, to unearth the cultural, racial empathy we have been lacking amongst ourselves since 1840.
It's probably a miracle that we have never incubated our own Māori/Pakeha hate crime. Because you don't have to dig too deep to still find a rich vein of Māori/Pakeha racism.
Put your religious convictions aside for a second and consider how the Muslim community have responded to what happened on March 15, 2019.
Humility. Grace. Love. Forgiveness.
There are many lessons to be learned from Christchurch. One is stop kidding ourselves, grow up and start showing the tolerance and empathy that will set an example for the rest of the world.
We're not quite there yet, but the beauty of a small country, as Jacinda Ardern demonstrated this week, is that you can implement change quickly.
Finally, a parting shot at social media. Facebook aren't going to moderate the content on Facebook, it's up to us. Don't tolerate hate speech.
Don't tolerate any conversation that has a tone escalated by anonymity, by not having to look the person in the eye, face to face.
Somehow we need to find a way to break open those incestuous hidden Facebook groups where like-minded cowards congregate and share fighting talk, encouraging each other to do "great" things.
As for Twitter, I've seen nothing this week to dissuade me from the view that it has its uses, but it makes me angry, when it becomes an echoing cavern of ill-informed, sanctimonious comment.
Am I grumpy? Sometimes. But right now, I'm also optimistic that out of this awful things, we will be better people.
The main thing? Let's not go back to thinking we're all good mates again.