“It didn’t make my parents happy at all, but I insisted on leaving school some months after the massacre. When I look back now, as a father, I take an even more complicated position on whether I made the right decision or not. The taxing demands I made on them as a teenager placed enormous strain on my parents, worsened by my post-traumatic stress disorder (PTSD), which intensified in the weeks and then months following the slaughter.

This meant that I never completed high school in South Africa. I knew at the time that there was no way that I could ever fit into my school or any other school again.

Although I had washed my hair, I woke up the morning after the massacre with shards of marble from the park bench on my pillow. I had escaped physically unscathed, but the real damage lay within. I have never recovered, emotionally.

The desolation of not having the school principal, or my teachers, or the other children – except a couple of close friends

– even acknowledge what had happened has remained with me to this day. I stayed away from school for five days, and during that time my parents organised for a psychiatrist to see me. But that lack of inquiry, care, compassion or basic humanity from the teachers and the headmaster left me overwhelmed with sorrow and distress.

I have yet to fill the hole that was left.

Even seeing the psychiatrist was complicated. The trauma left me so messed up, so unable to touch or feel what I had experienced that I fixated on the psychiatrist and her beauty instead. I couldn’t let go of that. I couldn’t focus on her efforts to reach me, and so the counselling failed.

As the days and weeks rolled out after that, it became difficult to manage my anger and dark moods. I was quick to anger and grew increasingly reserved. Soon, I was keeping mostly to myself. I lacked the life skills to process the trauma. Unfortunately, the level of emotional care and therapy someone would have access to today was not available to me back then.

A child today would be given time to heal, to be filled with fury, to heal again, and then to dip and rise – whatever was needed.

There was nothing like that for me in 1988, and I know there was nothing remotely like that for any of the victims – the injured and the bereaved families of the deceased – who happened to be on the square that day. Zero.

So my mind only raged. Bedtime became hellish. When my eyes finally closed, gore-filled and blood-drenched nightmares replayed themselves in my restless sleep. I’d wake up wet with sweat, the picture of a man writhing in anguish, flashing up again and again.

The spiral of sleeplessness and anxiety was relentless and destroyed any sense of normalcy. At the time, I wasn’t diagnosed with PTSD, as such, because it simply wasn’t well understood in those days.

I know, without knowing, that the other survivors of that day also exist with a tremendous anxiety set to trigger at the slightest provocation. I’ve thought so much about them, wondering where they are, and who they are, what happened to them, and how they’ve coped – or not coped.

I had no control over what I would do next, or even what my parents were capable of doing to protect me. That added to a perpetual feeling of vulnerability. Any tension I felt was met with a violent outburst. This behaviour was frightening for everyone who had known me as a happy-go-lucky, mischievous adolescent.

I argued with everyone and I got into fights. I was volatile and eventually, the lines that guided my sense of moral clarity began to blur.

Uninvited despair had swept into our family’s life and began to hurt my parents and others who had been close to me. My nieces were wary of my temper; other family members were concerned about their safety when they were with me. I know my parents were punished by all of this, and I can’t shake the remorse I feel around that, though I still don’t understand how such obvious symptoms of a developing depression were attributed to unruly behaviour.

One day, while I was at the servants’ quarters at the back of the townhouse complex where we lived to see a man we knew as Old Jonas, there was an aggressive banging on his steel door. Fear swept across Jonas’s face, but when my father’s voice sounded on the other side, he grinned in relief. I didn’t. I was clearly in trouble. My father was there to berate me.

‘Where’s your bike?’ Dad knew, just as I did, that it was lying in the middle of the street. ‘That’s it. I warned you,’ he said. ‘I’m donating it to a children’s home, to children who’d appreciate it.’I lost it. In a tantrum, I lashed out at Old Jonas’s meagre possessions. In a flurry of feet and fists, I annihilated his radio and milk-crate chair.

Jonas’s mouth hung open in shock. Sure, the destruction of property upset him, but he was more disgusted by the disrespect I’d shown my father.

A pair of wiry arms wrapped around my chest. Jonas’s tone was unambivalent.

‘Suga wena … keep quiet!’ he said, firmly. ‘No more talking to your father like that. Until you show your father respect, you are not welcome at my ekhaya.’

I know there are high numbers of children in South Africa today who have witnessed or have been affected by massacres, their parents or close family killed or injured, communities shattered.

Since 1988, there have been at least seven incidents that, like Strydom’s, have been deemed political. One was in Boipatong, a township near Johannesburg, in 1992 when 45 people were killed in bloody warfare between the ANC and the Inkatha Freedom Party (IFP); another in Bisho in the bantustan of Ciskei in 1992 where 29 people, mostly ANC supporters, were killed by government soldiers; then there was Kenilworth in Cape Town in 1993 when 11 worshippers were gunned down in St James Church by members of the Azanian People’s Liberation Army (APLA); Observatory in Cape Town in 1993 where three young people and a restaurant owner were killed by APLA at a popular student bar, the Heidelberg Tavern; Johannesburg in 1994 where 19 people were killed when 20 000 IFP supporters marched on the ANC’s headquarters, Shell House, to protest the upcoming first democratic elections; Shobashobane, 200 kilometres south of Durban, where 19 ANC supporters were killed by IFP supporters on Christmas Day 1995; and Skierlik, an informal settlement about two hours from Johannesburg, where a 19-year-old white extremist shot dead four black people. There was also Marikana, not far from Skierlik, where police opened fire on striking mineworkers in 2012, killing 34. All South Africans have their opinion on whether the latter was political or not.

These deaths are only a sampling of the lives lost since the Strijdom Square killing spree. This figure doesn’t include the multitude of people in South Africa slaughtered in taxi violence, hostel massacres, gang killings, family slayings and community and tribal killings, or the thousands believed to have died in scattered battles between the ANC and the IFP in KwaZulu-Natal before and after the first democratic elections. I’m in it. That’s the bloody truth. If I find myself in conversation with white people about white people killed by black people in massacres, I sometimes get to say what no one wants me to say: that I walked into the middle of slaughter by a white mass killer. And the only reason I was spared was because Strydom, a heinous individual, saw me as a fellow human solely due to my white-privileged skin. If I had been black, I would be dead.

That messes badly with my head. I see now that my actions in the years immediately after the massacre were probably all about that. Now the question is, can I twist those experiences into something positive? Many days, I don’t know if I can. There’s a mother lode of pretty bad stuff I have done, which I will tell you about. Many days, I can only try.

Occasionally, I believe I can achieve a positive outcome, usually after specific treatment, or when I maintain a consistent regimen with my meds.

Not long after I dropped out of school, my parents decided that joining the military might help bring order to my chaotic life. A week later, I’d passed my medical exam and I was soon on a train to Saldanha Bay.

The naval training base is a two-hour drive northwest of Cape Town. A few days later the reality of having leapt into the fire dawned on me as my head was briskly shaved to the texture of coarse sandpaper. That was when the navy formally notified me I’d been signed up to the Permanent Force rather than short-term civilian conscription. For some reason, my parents – who were able to make that decision on my behalf because I was not yet an adult – had neglected to tell me that. Considering the apartheid government’s desire to inspire an elite rank of military leaders, it was perhaps not ironic that the officer ranks of the SAS Saldanha were staffed with a dangerous bunch. When I joined up, rumour had it that the base commander, who had recently been demoted, had been reassigned to the training academy after ‘accidentally’ discharging a torpedo that happened to blow up a ‘friendly’ beach. And the senior instructor was under investigation for killing a fellow enlisted force member in a bar brawl.

From the outside looking in, the naval base was more like a brig with inmates running the show. But the fact is that I would fit in well with this band of ruffians – it wasn’t long before I broke a drill instructor’s nose and the navy tossed me in the kas, the jail cell on the base.

As I stared at the blank walls of the kas, I had time to think. A switch flipped in my head that I might as well become a well- trained fighting machine, considering I was already a failure at school and at home and had nothing to lose. I remember how I felt: this was the first time in my 17-year-old life that   I experienced such lucidity. No one would need to protect me – or fail to protect me; instead, I would be responsible for my own protection.

Back in 1989 the indoctrination we received in the armed forces had acute effects. Later, we used to joke about needing re-education camps, but perhaps that wouldn’t have been such a bad idea for my generation of white people. Seemingly, not many have emerged from that training able to say they regard their black compatriots as equals.

But once I’d embraced my own decision to excel as a formidable navy recruit, nothing at SAS Saldanha seemed too hard. The more focused I was, the stronger I became.

Training was tough, especially the 48-hour marches without food and sleep, and only rationed water. We called them opfok marches. At times, the instructors would load us – in full fatigues and wearing that horrible piss pot they called a helmet – with rifles, steel bed-frames, telephone poles and truck tyres. We were then ordered to lug this unbelievable weight along tarred roads, through ankle-sucking beach sand and over shifting dunes. The weather was without conscience; the rain poured down on us, the sun scorched us, and the wind swept us raw.

This physically and emotionally sapping routine was hard on lots of the guys. I was convinced I had to be especially on my guard and more resilient than the others enlisted in that academy because I was not only the youngest but also a high- school dropout. That didn’t mean, though, that I couldn’t wait for the basic training to end. I would repeat the SADF mantra: ‘Vasbyt – min dae.’

There were other mantras. A favourite of the naval trainers was: you panic, you die. And there was nothing like practical application to prove that point. Later, when I was based in Simon’s Town, we were expected to dive 20 metres into the ultra-black darkness of the drainage tunnels that filled and emptied the dry dock, just as an exercise.

One day, before I’d acclimatised, an instructor knocked away my sealed mask. A noxious blend of salt water and ship diesel rushed up my nose. In a nanosecond my panic level zoomed to eight. But I dealt with it, until I was sabotaged again – my oxygen regulator was ripped from my mouth and hidden around the back of my tank.

I choked on the flood. My gullet seemed to shrivel in the smothering fluid. After thrashing about in that watery vault, I began to play Blind Man’s Buff in a murky 6×6-foot tunnel until I found my dive buddy and shared his regulator until my heart rate decelerated. At that point the instructor yanked my dive buddy away, leaving me floundering again, but my panic had evaporated in those moments of calm when I shared my buddy’s air. I thought I’d figured out survival, that I had got a handle on my adrenalin and had understood my fear threshold.

I had graduated to Able Seaman by the time I was assigned to the SAS Chapman in Simon’s Town. I’d hoped it would be a combat ship, maybe a frigate, so I was disappointed when I discovered that it was a land-based dockyard. But I was to experience one of the most important shifts of my life on that base, which was, in fact, the hub for operations and intelligence support for the entire South African Navy.

I was experiencing many things for the first time in my life, and here I was given proper responsibility. I was appointed as a specialist in the navy’s Signal Intelligence Unit (SIGINT), my main task being to monitor Russian ‘fishing trawlers’ positioned around our vital shipping routes. Porcupine clusters of spiked antennae emanating from those trawlers clearly showed the true purpose of those vessels.

Sure, fishermen dragged nets and lines behind the sterns and hauled up rich offerings from the chilly Benguela current curling around the Cape of Good Hope. But that only added insult. A treasure trove of fish – kingklip, snoek and Cape hake – from South Africa’s territorial waters was subsidising their nefarious activities, while they dragged in a great deal more than a good catch. These Soviet AGI (Auxiliary, General, Intelligence) ships were fishing our airwaves for information about the status of our armed forces, naval and commercial fleet, and secured communications from the maritime headquarters in the underground Silvermine bunker, where I also worked.

Despite the outward ragtag appearance of these fishing trawlers, each carried state-of-the-art intelligence-gathering equipment for the Russian SIGINT and Electronic Intelligence (ELINT). All these vessels had a military bite. The sailors were trained and armed, and the boats held hidden caches of small-calibre cannons and torpedoes.

Sometimes a trawler would even shadow South African Navy vessels into international waters. This had apparently tested the patience of one of our captains. A crewmate told me, ‘The old man was really pissed off when one of those Russkie trawlers got in his way during a manoeuvre. So the captain sent a chopper and bombed the trawler with the ship’s garbage. He damn near caused a global incident.’

During my service, I was seconded for six months to a unit of the army that took me up to the Caprivi Strip, a guitar-neck- shaped corridor that extended from the north of Namibia to its neighbours Angola, Zambia and Botswana. The strip had been the launch pad for the army’s incursions into some of the Frontline States (FLS), which were, in fact, the nub of a formal entity within the Organisation of African Unity (OAU). By 1980, when Zimbabwe gained its freedom from white minority rule, the FLS consisted of Zimbabwe plus Botswana, Tanzania, Zambia, Angola and Mozambique.

During my time as a soldier in the Caprivi Strip, the FLS were chaired by Zambian president Dr Kenneth Kaunda, who, for us young defenders of the white realm, was no benevolent figure.

Zambia had been independent for about 26 years when I was wearing the SADF uniform, and Kaunda – the founding president of an African country – was known to us as the enemy. South African children of the apartheid era weren’t exposed to the rest of our continent, and neither were they to us. To the rest of Africa, the despicable policies of the apartheid regime meant that we were nothing more than pariahs and so, for the most part, Africa, as a broad swathe, was hostile.

Once you went into the SADF – which was restricted mostly to conscripted white boys and men aged 16 and upwards, by virtue of an amendment to the Defence Act in 1967 – you were introduced to African ‘friends’ such as the Angolan ‘rebel’ movement UNITA (National Union for the Total Independence of Angola) for the purpose of aiding UNITA in its mission to destroy the Soviet-sponsored MPLA (Popular Movement for the Liberation of Angola). Angola’s brutal civil war dragged on until 2002 and in this meat grinder numbers of SADF army troops died in a war sold to whites as an anti-communist drive.

By the time I found myself in the Caprivi, that was the lie of the land for us young white soldiers. This was a key point for what became known as the ‘Border War’, with the SADF firmly established as a violently stubborn bulwark against socialist Angola.

In some ways, I arrived in the Caprivi at the right moment because everyone stationed along those borders, from all sides, was engaged in what could be described as an ‘armed ceasefire’. Mine was a conventional tour of duty and one in which I did some signals intelligence training.

This didn’t mean we weren’t in danger, though. We could be mortared at any time, and every step we took on patrol felt like taking our chances on a roulette wheel because there were inevitably ‘black widow’ antipersonnel mines buried in the parched terrain of that crossing. Being sheared in half for putting a foot down on the wrong patch of African earth felt like bullshit to me.

The navy, on the other hand, had pointed me in a new direction. Pushing my teenage self to the limit, I became a competent shot, could handle myself in a proper scrap, and learned the rudiments of military tradecraft. All seemed to be going well, until I rammed an officer up against a window because he would not grant me leave to visit my father when he suffered a heart attack. Rather than go through the inconvenience of a court martial, I was honourably discharged. By then, the intelligence bug had taken hold.

I decided to make the Mother City my home, and in order to survive, I needed a job. My résumé was short. It read: ‘Thug for hire. Highly qualified.’ DM

Daily Maverick assistant editor and author Marianne Thamm will be launching Undercover with Mandela’s spies at Exclusive in the Waterfront on Tuesday, 4 June.