In “A Natural History of Human Emotions,” however, the cultural historian Stuart Walton argues that boredom, as a Western cultural trope, was basically invented yesterday. It dates, Mr. Walton says, from the mid-19th century, when the angsty concerns of the European leisured classes were immortalized in dissections of ennui such as “Anna Karenina” and “Madame Bovary.” (One suspects the anonymous Industrial Revolution proles who supported this enervated elite grappled with their own debilitating variety of boredom, albeit inside the murky warehouses of soul-crushing, robotic labor.)

The classicist Peter Toohey digs deeper. In “Boredom: A Lively History,” Mr. Toohey cites a plaque unearthed near Naples that honors a Roman worthy named Tanonius Marcellinus for having “rescued the population from endless boredom,” probably by sponsoring gladiatorial games. (Our salvation from boredom has evolved from spilling real blood in sand arenas to spilling pixelated blood in Mortal Kombat. Let’s be charitable and call this progress.)

But what about way back when? What of the ancestors whose forgotten migrations I am following? The nomadic Pleistocene hunter-gatherers who populated 95 percent of human history and who conquered the planet for us? Life in the Stone Age was hard. It was short. But it probably didn’t lack for idle afternoons.

Many anthropologists note that hunter-gatherers spend far less time “at work” than we do. African nomads like the San of the Kalahari Desert devote between 12 and 19 hours a week to securing their basic needs for food and shelter, as opposed to a harried 40-hour-a-week American.

I happen to think the seeds of boredom were planted along with the first wild cereals sown, possibly somewhere in the Near East, around 12,000 years ago: with the rise of agriculture. Farming rooted us to one spot and locked us into the treadmill of circular, monotonous lives. But clearly, there is more to boredom than what clinicians and historians can tell us.

As I prepare to set out on the next phase of my long trek, into the colossal steppes of Central Asia, I think about my past 1,000 days on foot.

My “work,” such as it is, is simply this: to be awake. You can sleepwalk your way through a relationship or a soul-smothering job. (I have.) But you cannot sleepwalk your way across the scorched Hejaz dune fields of Saudi Arabia. Because if you do, you won’t come out the other side. Naturally, this doesn’t preclude states of reverie, wakeful dreaming, which are long associated with foot power and are anything but boring.