‘DID you hear someone brought a gun on the ship?” It’s breakfast time on day one of my first cruise, and this is a lot to take in over my Eggs Benedict and pineapple juice. Someone did what?

It sounded dramatic, but the details turned out to be much less so – at least if taken at face value. A husband, wife and child boarded the ship at Miami with their luggage, which was passed through an airport-style scanner at the port. There, in one of the suitcases, in the pocket of a jacket, was a small, unloaded handgun.

The husband was taken by surprise, it seems. He’d completely forgotten it was there. It was only a small gun, he’d pointed out, and he’d packed no bullets. But a zero-tolerance policy is a zero-tolerance policy, so it was back on to dry land for Mr Pocket Pistol. The cost of a week’s cruise might have seemed a high price to pay for a thoughtless mistake, but the lesson learned was surely priceless, especially with a child at home.

“If you can’t remember where you put your gun,” observes my cabin neighbour sagely, “you probably shouldn’t have a gun.”

It’s hard for an outsider to truly understand America’s relationship with lethal weapons, or its responses not just to the shootings that make global headlines, but the daily

gun-related tragedies that don’t.

Thousands are expected to gather tomorrow in Washington DC, and cities across the United States, as part of March For Our Lives, a rally demanding tighter gun control in the wake of the mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida.

To those of us looking on from afar, it seems as though change must, finally, be coming. But for those raised to believe the Second Amendment was intended to protect the freedoms of individual hobbyists, regardless of the threat they may pose to the wide community, this is just another bow-and-arrow attack on the all-powerful National Rifle Association.

While the surviving students demand meaningful, nationwide reforms, Florida officials have come up with some of their own solutions. They’re going to give every student an ID badge and a transparent backpack. They’re installing metal detectors and upgrading surveillance systems. The theatre of security is intended to make students feel safe.

For student Kyra Parrow, it’s having the opposite effect. “More therapy dogs, less helicopters please,” she tweeted on Wednesday as the sound of buzzing blades disrupted her lessons. Twelve hours later, a plaintive update: “I just want my old life back.”

Back on the cruise ship it’s dinner time, and I’m the one bringing up guns: the ones visible on every other block in Roatan, Honduras, where our ship docked the previous day. Police with guns. Security guards with guns. And presumably, out of sight, ordinary residents with guns. Clearly the local authorities are deadly serious when they advise tourists against exploring alone, or venturing off the beaten track. The homicide rate for 2017 was a staggering 42.8 per 100,000 residents. Incredibly this represented a 25 per cent decline on the year before.

It would be awful to live somewhere so dangerous, we all agree. But it’s all relative, isn’t it? My American dinner companions may live in quiet suburbs or gated communities where they feel safe, but the presence of guns – in pockets, in opaque backpacks, in homes – means a vastly increased risk of them being murdered, or accidentally shot, compared to people in the UK.

Without WiFi and suffering from news deprivation, I ask a fellow traveller from Alabama to provide me with a quick fix over dessert. Stephen Hawking has died, he informs me. A pedestrian bridge has collapsed in Florida, crushing drivers underneath. Oh, and in his home state a gunman is on the loose in a hospital. It’s not yet know if there are any casualties.

On my return home, I look up the details. The shooter, swiftly and neatly categorised by the media as a “disgruntled employee”, killed a nurse manager and injured another worker before turning the gun on himself. It’s hard to imagine any scenario more frightening than a shooting in a hospital, but the incident will likely already be fading in the memories of all but those directly involved, given the state averages more than one murder or manslaughter per day.

The homicide rate in Alabama is the third-highest in the US, and seven times that of Scotland. The rate in Honduras may be one of the highest in the world, but it’s only five times that of Alabama.

I’m left pondering the man who missed his cruise. When pleas for improved mental health care are issued, the focus tends to be on angry – disgruntled – young men. But what of older, ordinarily responsible gun owners whose faculties start to fail? Who might,

for example, forget where they’ve put a weapon?

The Alzheimer’s Association notes that “as the disease progresses, people with dementia sometimes misperceive danger and may do whatever seems necessary to protect themselves, even if no threat exists”.

There’s little point trying to challenge the right of Americans

to bear arms: such efforts simply won’t succeed. But that right cannot be absolute, and with any right comes responsibilities. It’s time for US legislators – as well as individual gun owners – to start living up

to theirs.