" 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; like the old in America generally, either invisible or someone to ignore rather than respect, who will be gone soon, and forgotten, 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. And I think of myself in the Mexican way, not as an old man but as most Mexicans regard a senior, an hombre de juicio, a man of judgement; not ruco, worn out, beneath notice, someone to be patronized, but owed the respect traditionally accorded to an elder, someone (in the Mexican euphemism) of La Tercera Edad, the Third Age, who might be called Don Pablo or tio (uncle) in deference. Mexican youths are required by custom to surrender their seat to anyone older. They know the saying: Mas sabe el diablo por viejo, que por diablo - The devil is wise because he’s old, not because he’s the devil. But “Stand aside, old man, and make way for the young” is the American way.
As an Ancient Mariner of a sort, I want to hold the doubters with my skinny hand, fix them with a glittering eye, and say, “I have been to a place where none of you have ever been, where none of you can ever go. It is the past. I spent decades there and I can say, you don’t have the slightest idea. "

― Paul Theroux , On the Plain of Snakes: A Mexican Journey