One of the few benefits of growing old is that your frame of reference grows with you. Personal memory is notoriously unreliable, of course, but there are some things – and some people – you never forget.

Take Mitch the Marine, for example.

He came into my life, briefly, in March 1981, when I was hitchhiking across the USA. I was a young man on an adventure, and Mitch gave me a lift from Nashville TN to Durham NC.

Two things stick in my mind from that more than 500-mile ride.

The first was Mitch himself. He was a slight, wiry, figure who didn’t conform to my imagined stereotype of a US Marine. While he drove, he toked on a stubby wooden pipe filled with hash and for much of the time seemed lost in his thoughts.

He told me he’d been in the military all his adult life, had served two tours in Vietnam and was now a Master Sergeant.

An hour or so into the ride, after a silence, he asked a question.

‘You heard of My Lai?’

I was startled. ‘What, as in the My Lai massacre?’

‘Yuh.’

I had heard of it. I was only a kid at the time but it was an infamous episode during the Vietnam War. US soldiers had murdered hundreds of civilians – women, elderly men and children – in the village of My Lai during a search for enemy Viet Cong.

The massacre was hidden by the US Army but uncovered by a whistleblower and the journalist Seymour Hersch.

The outrage was loud and universal. The officer in charge was jailed for life (later commuted by Nixon to three years of house arrest); and the event served to fuel the growing domestic opposition to the war.

‘What about it?’ I asked.

‘Happened all the time,’ said Mitch. ‘You’d go into a village, with these long bamboo poles, and you’d prod the ground, looking for tunnels, foxholes, weapons. VC. And if you found anything – you just wasted everyone.’

A pause as I processed the information.

‘Did you do that?’ I asked.

‘No,’ said Mitch. ‘But I was there when it happened.’

We drove on in silence. Mitch was not just lost in his thoughts, it seemed to me; he was haunted by them.

Then the second thing that sticks in my mind.

As we drove east in the fading light and up into the Great Smoky Mountains that straddle the border of Tennessee and North Carolina, it started to snow.

And snow. And snow.

Soon it was coming down in such thick lumps that the wipers could barely clear the windscreen. The traffic on the freeway slowed to a crawl, then a stop. I got out to look for the reason. Up ahead, red taillights as far as the eye could see through the blizzard. Behind, a long line of blazing headlights in the whirling snow. Over everything, the eerie orange glow of the freeway lighting. And silence, apart from the biting wind.

We couldn’t go forward, couldn’t go back – we just had to wait till we got moving again. But we had a problem. The tank was almost empty so we couldn’t run the engine to keep warm. Mitch had to switch off the electrics, too, including the wipers, to save the battery. Which meant that as the snow settled on the windscreen, the orange of the freeway lights would get dimmer and dimmer, until we were sitting in total darkness. Like in a tomb.

Periodically, Mitch would turn the engine on for a blast of heat and to clear the windscreen, then quickly off – until we started to shiver again.

Rinse and repeat – for hours.

It was a strange experience. At one point, Mitch’s voice came out of the darkness to my left.

‘You know, Eddy, I’m glad you’re here.’

Rescue came in the early hours of the morning. A snowplough and a tow-truck somehow managed to forge a path up the mountain and clear away the lorry that had jack-knifed across the freeway up ahead. In time, the traffic started to inch forward – then suddenly we were free.

Mitch said goodbye to me at a Dunkin’ Donuts on the edge of Durham at 4.30 in the morning, nine hours after our anticipated arrival time, and drove off into the dawn light.

I never saw him again.

So what prompted me to think of him now, all these years later?

Well, I recently read a news report about the IDF – ‘Israeli soldiers speak out on killings of Gaza civilians’.

More than half a century on, there will be no global outrage, no one will be held to account, there won’t even be an enquiry. Unlike My Lai the whistleblowing from Gaza has come and gone with barely a ripple.

Because something has changed – information management, trust in the news, shared values. Perhaps even our ability to be shocked. So many of us  are simply in denial.

‘Did you take part?’

‘No. But I was there when it happened.’