Culture shock does funny things to you. I’ve long been an atheist, but my first exposure to the developing world opened a deep well of guilt that would impress the most avowed Opus Dei devotee.

I’m in Hanoi to meet two friends, also backpacking. Having been exposed to the extremes of India, they are unfazed by the grimy pandemonium of the Vietnamese capital, which leaves me slack-jawed and overwhelmed.

Then, for 72 hours, the downpour is unrelenting. We’re stuck in a dimly lit, cheap hotel and cabin fever sets in. We read online that it’s the heaviest rain in the city for decades. Flash floods and lightning have killed 20 people in northern and central Vietnam, including four in Hanoi. This is when the throat-tightening guilt sets in. I’ve been fed up while people were dying nearby.

We want to travel south by train and bus, but the train station is flooded and the roads are impassable. We’re marooned and losing days from our tight schedule. The deluge is set to continue for another week, so we decide to leave.

As the plane to Bangkok takes off, I feel relieved and then guilty again. I’ve often wondered idly what I would do if I were ever caught up in a natural disaster. Those daydreams usually involved me ministering tenderly to unfortunate victims or delivering solemn reports-to-camera while wearing a crumpled, white linen shirt. When I actually came close to what was, at least, a natural calamity, I drank beer and played cards in a hotel room, moaned about the disruption to my travel schedule, became cranky, and fled as soon as possible. It’s distinctly unedifying to realise you’re neither a latter-day Mother Teresa nor the next Orla Guerin.

The situation deteriorates in Hanoi after we leave: at least 100 neighbourhoods are flooded; almost 40,000 people are evacuated; power cuts are widespread; food and fresh water are in short supply; and the Health Ministry warns that cholera, typhoid and dengue fever outbreaks are likely. An eyewitness tells Reuters: “It is chaotic, like in wartime.” In all, 93 people die.

My mother e-mails to say she hasn’t seen anything about it on the news. In journalism college we learnt about proximity as a news value and I remember laughing at a notoriously dull newspaper headline from the 1920s — “Small earthquake in Chile, not many dead”. It seemed funny at the time.

The guilt subsides on the boat to Koh Phi Phi Don, an island in the Andaman Sea off Thailand. Tourism has helped rebuild it after the devastation wreaked by the 2004 tsunami. The sunshine bolsters my mood, as does the sight of longboats garlanded with flowers zipping between our ferry and the island’s perfect-white beaches, thatched bungalows and greenery-cloaked peaks.

After a couple of days I leave the island’s main village, which is vibrant and colourful. I pass shabbier guest houses on the outskirts and local housing — precarious, three-sided shacks built of plastic and corrugated metal. Some of the islanders are horribly poor. I’m so unnerved at this realisation that, when it comes to buying a necklace and bracelet in the village an hour later, the sales assistant has to haggle for me.

“Two together, 1,000 baht (about €22),” she says. I gawp blankly at her. She jabs at her calculator. “Okay, 800 baht.” I know the appropriate response is to make a disgusted face and proffer a few hundred baht. “Great!” I say, smiling sheepishly.

Later, at a beach bar, I discuss my embarrassingly persistent First World guilt with a well-travelled New Zealander. We’re surrounded by a few hundred backpackers partying intently, many drinking from small buckets of the local rum, Sang Som, mixed with the local version of Red Bull, which is rumoured (falsely) to contain amphetamines. Everyone, including the local bar staff, is enjoying themselves enormously.

“You can’t change everything,” he says. “You can only make little changes. You should haggle, because that’s business, not charity. If you want, give the money you save by haggling to an NGO afterwards. You can’t judge by our standards. People here aren’t poor. Everyone has enough to eat. In Angkor Wat in Cambodia you’d be surrounded by malnourished children with bellies sticking out and, even there, you’d just have to keep walking, because you can’t change everything. You can buy them some food or give money to an NGO, but that’s it.”

Later in the week, the monsoon rain catches up with us. In the village, a man on a bicycle splashes towards me. He has a homemade sidecar welded to his bike, a plastic carrier bag on his head — knotted hankie-style — and a ripped, black bin liner over faded T-shirt and shorts. “Beep! Beep!” he calls cheerily to a couple of sodden tourists blocking his way. I nod a greeting at him, tugging self-consciously at the hem of my North Face rain jacket. “Hydrenalite, windproof, breathable,” says the logo on the sleeve. I wonder crossly what the hell hydrenalite is.

I consider giving away the jacket, but I don’t. I duck into a café to escape the rain. I have lunch and leave a decent tip. I’m learning slowly — you can’t change everything.

kathy.foley@sunday-times.ie

Times Recommends

• Violent video games won’t corrupt
• Pope Benedict XVI: Alma Mater
• Chávez should know what’s good for him