Why would a reasonably sane man in his 70s ride the length of Hispanic America on a small motorcycle - a man who is overweight, suffered two minor heart attacks, has a bad back and survives on a small pension? Age has much to do with it. My wife is younger by almost 30 years. I suspect that our late-teenage sons find me an embarrassment. I am mistaken for their granddad - or an old tramp. And my tales of past travels bore them.
So an attempt to prove to myself and to my family that I can hack it? And to others of my age that solo travel remains possible and an enlivening experience.
I chose a Honda 125cc for the journey, the original pizza delivery bike. I could buy it new in Mexico for £1,200; it's built in Brazil, and spares are available throughout Hispanic America; it does 120 miles to the gallon; my legs have sufficient strength to hold it upright and I can lift it after a fall.
Finance and time governed my preparations. I bought a thick jumper and a pair of strong Church's walking shoes in a Hereford charity shop, packed thermals and a six-month supply of heart medication. Insurance? For a biker in his 70s? I don't think so.
A cheap ticket with Aer Lingus took me to Boston, followed by Amtrak south. I have treated the United States on past visits as widespread islands: New York, Los Angeles, Miami, Dallas. What land lay between? Mostly flat, was the answer; innumerable small towns of identical clapboard houses, rust-spotted gas guzzlers and monster pickups in the yard. I remarked to a fellow passenger on the US flag flying outside almost every house.
"The poor live close by the railway track. Their kids are in the military."
Arkansas was the surprise. I had imagined dirt farms. The reality was green hills and magnificent trees.
Finally Dallas and the home of an old friend, a true Texan. He and three fellow good ol' boys planned a weekend on monster bikes. I followed in a Hummer as baggage man.
Columbus claimed the world was round; he had never cruised the Texas Panhandle. The road runs flat and straight, not a house, no animals, not even a tree. The boys on the bikes rode in a bunch. Back home we would fill the road. In the Panhandle we were minute pieces in a board game. Reach the end of the board and we fall off.
I travelled by express coach south from Dallas to Veracruz on the Gulf of Mexico: 750 miles, 36 hours, $115. The good ol' boys had thought me mad. A bus driven by a Mexican - tantamount to suicide. And riding a tiny bike through countries plagued by banditry! Plus corrupt cops and border officials!
A new bike awaited me at the Honda agency in Veracruz. I was confronted by the first official when registering the bike. Proof of residence was obligatory. A utilities bill was sufficient. The registrar produced his own electricity bill and called me grandfather. Keep to the main roads, he warned. Elsewhere there are bandits. . .
I took the bike for a preliminary outing to Old Veracruz and the ruins of Hernando Cortés's first house. From here Cortés set out to conquer Mexico. Aztec armies must have been a doddle compared with traffic on the urban freeway. This was my first ride in 40 years. Three miles and my thumb and thigh muscles cramped. The project was ridiculous. Time to admit defeat. Return home, tail between my legs. Face the mockery of friends and neighbours.
I was saved by meditation. "Om" never did it for me - not even in the mystic 60s. At a riverside restaurant in Old Veracruz, I meditated on a dish of perfectly prepared prawns with chili - camarones el diablo. I breathed the familiar, thick, over-ripe tropical scent of garlic and onion, fried fish, fruit, rotting leaves and rich damp earth. A boat chugged up-river, birds sung, children chased each other, a fun trio played Mexican weep music. Bliss.
I was fortunate in Veracruz to meet a kindly Federal police officer with extensive knowledge of the roads. He suggested a suitable route for an elderly novice: the first day south along the coast to San Andreas Tuxla, straight road, gentle gradients; a second day of low hills followed by a stretch of highway to Tuxtepec; third day over the Sierra Juarez on Route 175 and my first mountain pass. Call me, he said, call me when you reach Oaxaca.
I stopped three times on the climb to add clothing. Hairpin followed hairpin, rainforest gave way to pine. Could the bike cope? Could I cope? Was the knife pain in my chest cardialgic, muscular or imagination?
My legs trembled as I dismounted at a mud brick cafe at the head of the pass. The woman owner set a chair in the sun, poured me a glass of freshly squeezed orange juice and shouted to her daughter to check the hen house for eggs. An old bus disgorged companionable faces. Where was I going? All the way south, I said - and, for the first time, believed that I might succeed.
Oaxaca is 16th- and 17th-century Hispanic colonial glory in green quarry stone, luminescent after rainfalls. The Jesuit temple is austere beauty. I discovered companionship in a side chapel - the familiar names of our English Jesuits engraved among the roll of martyrs: Owen, Oldcorne, Ashley, Campion, Arrowsmith. And I reported to the Veracruz Fed that I had arrived safely.
"I thought you would. Call me from Ushuaia."
I recall a perfect dawn on Mexico's Pacific coast. From Tehuantepec an excellent highway unwound west through hills speckled with white blossom of frangipani and splashed with creepers of deep rose and brilliant blue. Rain left a sharp, clean taste to the air. I glimpsed, between the hills, sea and white surf curling on golden sand; vultures and buzzards floated overhead. I rode at ease among memories of my Bultaco trail bike in the Ibiza of the 60s.
Indulging in memories is dangerous. My Guatemalan friend, Eugenio, owns a Maya hill tower overlooking the Rio Dulce. "The track's bad," he warned. "I'll run you up later in the pickup." As if I was an old man in need of help!
Proud in my Ibiza memories, I kicked the Honda alive. Minutes later I lay beneath the bike, my right leg frying on the exhaust pipe. The burns became a battleground between modern pharma and ancient brujaria, antibiotics versus jungle poultices,
Falls are unavoidable. My second came on Costa Rica's Nicoya Peninsula, a steep gravel road. Diners gathered round as a doctor scrubbed and sewed my right hand at a table in a village restaurant. I sat with my eyes shut and concentrated on the kitchen scents of garlic and grilled snapper.
Two days' rest in a cabin behind the general store in San Francisco de Coyote and I was off again, up over the mountain spine, Pacific Coast to the Caribbean - and a third tumble, this time on a United Fruit Company railway bridge a few miles into Panama. The bridge is 100m long. Planks either side of the rails form the roadway. The planks were slippery and uneven. Some were missing. Much of the safety rail had been torn away. I panicked and deliberately tipped the bike inward between the rails. Truckers rescued me and delivered me and the Honda to the next town, Almirante.
The customs chief at the Honduran border was the only official to hold me up. He insisted I watch a France v Mexico football international on the TV in his office - and drink his beer. I demurred at the third bottle. Copan was my destination. Six miles, old man. You can slide that far.
Nor can I complain of the law. Lost in Bogota, two biker cops led me a few miles to the highway with blue lights and sirens. Traffic police nurse-maided me through the coastal desert of Peru in a sandstorm and treated me to lunch. A police band in Bolivia played me out of town. A female police officer in Salta, Argentina, kissed me on both cheeks.
Dangers? Colón, Panama, was dangerous. Police armed for a war zone patrolled in pairs and radioed back-up to escort me a single block to a bank. And I met a Chinese American biker who had been robbed at knifepoint. He and I were seeking passage round the Darien Gap. We shipped on a small banana boat only to discover that the crew were smugglers. We had paid to be delivered to Cartagena. They dumped us on a beach in the middle of the night. We were in Colombia illegally. The nearest town, San Bernardo, was an hour's ride down a mud track. A further six hours brought us to Cartagena to be chided by the head of immigration: "Safer for them to have cut your throat. Have you learned nothing in your 70 years?"
Colombia has an image problem created by Hollywood. Scenery is jungle. Men sweat and wear grease in their hair. Intrepid US heroes (Harrison Ford) fight cocaine cartels. Heading inland I rode through a vast parkland of great trees, lush paddocks, fat cattle, glossy horses - followed by days of mountains and upland pastures reminiscent of the English Lake District.
And such urban architecture - from the simplicity of small, cobble-and-whitewash towns to the 17th-century glories of Cartagena and Popayán. I find Popayán, founded in the 16th century, to be the most perfect of Hispanic colonial towns. Streets of baroque houses and mansions remain unblemished by developers. Cathedral and churches possess a serene beauty.
Ecuador boasts the glories of Quito and, at the Museo Nacional, Hispanic America's greatest collection of pre-Columbian ceramics. Peru and Bolivia are the tarns and fells of the Alto Plano, snowy peaks and the fifth day of a miners' picket that had closed the highway. The miners welcomed the grandfather. We sat on a grass bank, sipped mate, the ancient drink of health and friendship, and photographed each other.
Argentina is Salta and the culture shock of finding myself in a seemingly European city, the desert to Mendoza, delicious wine, huge steaks, the massive barrier of the Andes, the extraordinary clarity of light in Patagonia and, in driving sleet, surprise at startling a flock of green parrots from trees along a river bank.
Now returned to the safety of my beloved Herefordshire, I recall fragments of conversation:
A Mexican businessman in Veracruz commenting on race: "The only pure bloods are horses."
A mid-50s Californian surfer with chemically recalibrated brain insisting that 7ft aliens had been discovered in sarcophagi beneath Mayan pyramids.
A bench in the cathedral square, Panama, and an elderly schoolteacher weeps as she recounts the US invasion: "None of the captains were killed. Only poor people. My neighbours were all killed. The youngest girl was six. The grandmother was 73. And my sister . . ."
My Chinese-American companion on the smugglers' boat from Colón to Colombia remarks at every setback or danger: "Simon, we wanted an adventure . . ."
Puerto San Julian, Patagonia, an elderly matron at the monument to the heroes of the Argentine airforce in the Falklands/Malvinas War: "It was a politicians' war. There were no heroes, only victims."
Finally, the manager of the Honda agency in Ushuaia: "We've been expecting you, Senor Gandolfi."
My journey was complete: six months on the road, 16,000 miles on the clock, a maximum ascent (in Bolivia) of 4,700 metres. I was treated, universally, even in Colón, and by officialdom and commonality, always with true kindness and consideration. I slept in small family hotels recommended by locals, invariably a room with a bath. Room rates varied from country to country: US$18 in Veracruz, half that in Bolivia.
I come from a recusant family and was educated at Catholic schools. In the sublime churches of Hispanic America I discovered how deeply imbued I am with the culture of Catholicism . . . And, riding alone across those vast spaces, uncovered within myself an unfashionable admiration for those scant bands of Spaniards, the Conquistadors. They were small men of minimal education and many superstitions. Judge them how you wish, but never doubt their extraordinary courage and imagination.
And they differed in one essential respect from the British Founding Fathers of the United States. The Conquistadors intermarried with the indigenous population . . . Yes, including Hernando Cortés.
• Old Man on a Bike by Simon Gandolfi is published by The Friday Project, £8.99.