His survival instincts unexpectedly but reassuringly turned him into an "extremely good fighter".
It had dawned on him that people tended to act differently when in groups, as opposed to individuals.
"So someone who talked to you individually quickly became bullies when they retreated into groups."
A "smart arse", Hanlon soon devised a theory that group intelligence was a figure that could be divided by the number of individuals and then halved to come up with a quotient.
His books have broached the subject of how racial discrimination is not inherent, but something learned.
He remembers arriving on his very first night at boarding school to find scores of peers bawling their eyes out, "wanting their mums".
"When I got to high school I was 12 years and one month old.
"They were all 14 and worked on farms so they were bigger and stronger but crying like babies," he says.
"I remember sitting there thinking, 'Well, like a Monty Python thing, you're all sad but I won't see my parents until December and yet you'll see your parents next weekend, you big sissies'," he says while recounting a Lord Of The Flies-type scenario where they turned on him within three days.
The conch shell-toting mob often picked on anyone who strayed from the norm, something he feels is still prevalent today.
"The slow kid, the fat kid or the mummy's boy - they were all getting picked on.
"In actual fact I was doing well. I was smart and at the end I could remember the three years because I had some of these bullies coming to me, cap in hand, asking me to help them so they could pass their exams."
He somehow got around to forgiving them all. On returning to Auckland at 15, he recalls a former boarder asking him if he was Johnny Hanlon.
"Very few people called me John when I was in boarding school.
"You know, I was always a chink, anthracite [submetallic luster coal] or coal hole. I was always some stupid name.
"Only six people called me by my name, right, and half of those were teachers," he says.
Hanlon often ponders on whether those bullies, when they became adults, ever reflected on "why they were such arseholes to this guy".
Sport savvy, he got vociferous approval from the bullies when he dived into the competitive lanes of a swimming pool, despite playing second fiddle to the state champion at his school.
His parents thought he was outstanding in the pool. He disagrees although he did them proud as a gymnast.
"In boarding school that's all you did - study and play sport. You didn't even have to be smart to get scholarships. You just had to show up."
