Tired as a well-worn cliché, I finally reached Ciudad Cahuatemoc, a "city" on the Guatemala-Mexico border, that consisted of two identical wooden shacks, one a customs shed, the other a bar. Lying on a wobbly bench in front of the shack marked "aduanas" was a fat, mustachioed immigration official, his face contorted as if he'd just bitten into a lemon. "Que quieres?" he barked as I approached. I leapt back a step. I thought he had been napping.

"Por favor senor, me gustaria entrar Mexico," I pleaded in halting Spanish.
"Are you a hippy?" he replied eyeing my shoulder-length hair. His arrogant, mean-spirited demeanour left me momentarily speechless. I put down my rucksack, dug through my money-belt and handed him my passport. He continued to glare, struggled out of his chair, turned and disappeared into his dark office. I followed him in.

"Con mucho respecto senor, I beg permission to enter your wonderful country."
He limped behind his imposing desk and flipped through my passport.
"Your immunisation certificate," he ordered.
"I don't have one," I admitted weakly.
"What a shame," he said, breaking into a ruthless, gold-capped grin, "There is much yellow fever in Guatemala."
Before I could begin to argue he opened a small drawer and pulled out an ancient syringe with a huge rusty needle attached. "But you are in luck my friend, we provide cheap immunisations here. " For the second time in minutes I was speechless. He savoured the moment and my expression of abject fear, then threw down the needle and slapped me on the shoulder in his first convivial gesture. "You gringos never understand our Mexican sense of humour." He roared with laughter. I breathed an inward sigh of relief. "Of course, if you're afraid of needles we sell suppositories at a very reasonable price…."

A few minutes later with an entry stamp in my passport and a ten-dollar "contribution" stuffed in his shirt pocket, he closed up shop and we ambled over to the cantina.
"Una cerveza por mi amigo," he bellowed as we sidled up to the bar. By our third shot of tequila we were the best of buddies. Jorge waxed rhapsodically about Princess Diana, James Bond and Manchester United. I sang the praises of Carta Blanca, Jose Cuervo and Salma Hayek.

When the time came to pay for the drinks I sheepishly opened my empty wallet. "I hope your Mexican sense of humour is in tact because I just spent my last ten dollars on health insurance."

Jorge leered at me for a moment, his huge body swaying, swept up in profound indecision. Then a giggle squeaked through his defences, quickly turning to laughter. Within seconds, he was in hysterics, braying like a wounded donkey. He laughed so hard and long I thought he would have a coronary.

Finally catching his breath, he clasped me around the shoulder and ordered another round of tequilas for the road.
"Salud!" he shouted.
"To your good health," I replied.