There are times when you have no choice but to ignore your own guide book's advice. I had to get from Nazca to Lima and the only option was a night bus. The South American Handbook is quite forthright on this point: if at all possible, avoid night buses and do not arrive in a big city in the dark. But there I was, proposing to take a bus departing before midnight for the six-hour journey to the capital, in other words, getting there before dawn. Oh well, the journey had to be done and there was no flight.

I settled into my reserved seat and prepared myself mentally for a few uncomfortable, sleepless hours. A man sat next to me, said good evening, and settled down too. Once we were on our way, my neighbour offered me a sweet. More advice from the handbook, namely the How To Keep Safe paragraph: "Finally", it urges, "never accept food, drink, sweets or cigarettes from unknown fellow travellers on buses or trains. They may be drugged and you would wake up hours later without your belongings."

I can't recall how many times I have read that phrase, wondering each year whether it is still a pertinent warning. All the same, I don't recall it flashing through my mind on this occasion. I must have been on autopilot when I declined.

Unusually for me, I did fall asleep and the whole journey passed in the land of nod. When eventually I awoke as the bus pulled into Lima, my neighbour had gone. So had my wallet. The anger that I felt at having had my pocket picked was at least tempered by that little editorial voice that had said "Don't take the sweet!" If I had, what else would I have lost?

Waiting for the dawn in the grubby bus terminal, I clung to my belongings as tightly as I could and turned down every hawker's offer of food or drink, factory-sealed or not.

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