In the casual opinion of most Americans, I am an old man, and therefore of little account, past my best, fading in a pathetic diminuendo while flashing his AARP card, a gringo in his degringolade. Naturally, I am insulted by this, but out of pride I don’t let my indignation show. My work is my reply, my travel is my defiance .

Sometimes, a single person, met casually on a journey, can be a powerful inspiration. I happened to be in Nogales, Mexico, to talk to migrants — and on that visit I saw a middle-aged woman praying before her meal in a shelter. She was Zapotec, from a mountain village in Oaxaca state, and had left her three young children with her mother, intending to enter the United States and (so she said) become a menial in a hotel somewhere and send money back to her family who were living in poverty. But she had become lost in the desert, and spotted by the Border Patrol, seized and roughed up and dumped in Nogales. The image of her praying did not leave my mind and it strengthened my resolve to take a trip throughout Mexico, but concentrating on Oaxaca, one of the poorest states; and on my trip whenever I felt obstructed or low, I thought of this valiant woman, and moved on.

I studied the map. I had no status except my age, but in a country where the old are respected, that was enough — more than enough.

So I took an improvisational road trip along the border and the length of Mexico, from the frontier to Chiapas, with the kind of excitement I felt as a young man. One of the greatest adventures of my traveling life, this trip on the plain of snakes (as I thought of it) was enlightening and pleasurable, Mexico’s splendors vastly outweighing its miseries, and, though I had been warned repeatedly beforehand, I did not die.