By M. Andrew McConnell
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April 28, 2026
For roughly 199,800 of our 200,000 years on this planet, no human ever moved faster than a horse. Think about that. Across nearly the entire arc of human evolution, the upper limit of how fast a body could be hurled across the surface of the earth was set by hooves. You could not, under any circumstances, eat breakfast in London and dinner in New York. The very idea of crossing five time zones in a day would have been incoherent — like asking someone in 1450 what their Wi-Fi password was. Then, in the blink of an evolutionary eye, we built jets. And our bodies have been paying interest on that loan ever since. The Bargain We Made With Speed Jet travel is, by almost any measure, miraculous. I can hug my daughter in Bermuda in the morning and shake a client’s hand in Los Angeles by dinner. Families separated by oceans get to be families. Markets that used to take six months to enter take six hours. Ideas, goods, and people move at a pace our great-grandparents would have found indistinguishable from magic. But every frequent flyer knows the other side of the ledger. You get off the plane and your body is, quite literally, in the wrong time zone. Your circadian rhythm — a system tuned over millions of years to the rotation of a single planet — is suddenly out of sync with the sun outside your window. You can’t sleep when you should. You can’t stay awake when you need to. Your digestion is off. Your judgment is impaired (studies put a sleep-deprived, jet-lagged brain in the same cognitive ballpark as a legally drunk one). You feel, for a few days, like a slightly broken version of yourself. This is what happens when technology lets the body travel faster than evolution prepared it to travel. Here’s the thing: I think we’re now living through the cognitive version of the same story. Welcome to Mental Jet Lag For most of human history, a person could think one thought at a time, work on one problem at a time, hold one conversation at a time. Even the most brilliant polymath was bottlenecked by the simple fact that there was one of them. Now? I can have four Claude tabs open writing in parallel. An agent in the background combing through my inbox. Another summarizing a 90-page report. A research tool building me a competitor analysis while I’m on a Zoom. I can — and on a busy day, I do — carry on a dozen “conversations” with various AI systems simultaneously, each operating at a pace no human collaborator could match. The output is staggering. I get more done in a Tuesday morning than I used to get done in a week. But somewhere around 4 p.m., something happens that I didn’t expect. It’s not the familiar exhaustion of a hard day’s work. It’s a different feeling — fuzzier, more diffuse. Like my brain has just stepped off a flight from somewhere it was never meant to go. I’ve started calling this mental jet lag : the cognitive and physiological cost of operating at a pace your nervous system has not evolved to handle. And just like the airborne kind, it comes with a real bill — one most of us are paying without ever seeing the invoice. The Symptoms If you’re using AI tools heavily, see how many of these you recognize: Decision fatigue at unusual hours. You’ve made more micro-judgments by lunch — “is this output good? does this draft work? should I refine or restart?” — than you used to make in a full day. Each is small. The pile is enormous. The “fuzzy brilliance” feeling. You’re producing more, but you can’t quite remember what you produced. The work flowed through you rather than from you. A weird kind of loneliness. Hours of “conversation” without a single human voice. The social pillar of human cognition — the thing that, biologically, has kept us regulated and resilient for 200,000 years — gets quietly skipped. Compressed creative timelines that don’t actually feel creative. The marination time, the showering-and-suddenly-having-an-idea time, the “let me sleep on it” time — gone. Replaced with “let me prompt on it.” Physical signs that mimic actual jet lag. Disrupted sleep. Tension headaches. The hollow-eyed look of someone who’s been staring at screens that talk back. Elevated cortisol. The body keeps the score, even when the score is being kept by an LLM. The “infinite to-do list” effect. AI removes the friction that used to cap your ambition. The list of “things I could now do” expands faster than the list of “things I have done.” The gap is where anxiety lives. None of this is an argument against AI. I am, demonstrably, an enthusiast. But I’m also someone who spent years learning the hard way that the ability to keep going is not the same as the presence of health. We are, once again, mistaking output for vitality. We are, once again, treating biological hardware like it can be indefinitely upgraded by professional software. It can’t. What We Can Learn From Jet Lag Here’s the good news: humans are actually pretty experienced at this problem now. We’ve had about 70 years to figure out how to fly across the world and not feel like garbage when we arrive. The protocols are well-established. And almost all of them translate, with surprising precision, to the AI age. Anchor your circadian rhythm. Frequent flyers know: get sunlight at the right local hour, and your body recalibrates. The cognitive equivalent is anchoring your day in human-paced rituals that AI cannot accelerate. A morning walk before you open a single tab. A real meal at a real table. A conversation with another human being where neither of you is optimizing for tokens. These aren’t indulgences; they’re the cognitive equivalent of getting ten minutes of morning light. Hydrate and fuel the machine. Pilots will tell you that altitude dehydrates you faster than you realize. AI does something similar to your attention — it depletes a resource you didn’t know you were spending. Schedule recovery the way you schedule meetings. Treat focus like the finite, replenishable resource it actually is. Build in layovers. No serious traveler does back-to-back red-eyes for a week without consequence. Yet I know plenty of people (myself included, on bad days) who do the AI equivalent: multiple days of ten consecutive hours of high-cognition prompting with no break in between. AI has compressed to zero all the natural pauses that used to be built into knowledge work — the walk to a colleague’s desk, the wait for a reply, the time it took to actually read the thing. So the pauses now have to be put back in on purpose. Five minutes of nothing between intense AI sessions. A real lunch, away from the screen. A walk between agents. A genuine end to the workday, not “one more prompt” rolling into 10 p.m. And a weekend without any work — including the increasingly common move of “I had AI handle it over the weekend so I could relax,” which misses the point entirely. If you’ve outsourced the doing but kept the thinking-about-doing, you’ve changed nothing except who’s typing. Don’t fight the body — partner with it. The single biggest mistake jet-lagged travelers make is pretending the lag isn’t happening. They power through, crash harder, and lose three days instead of one. The same is true here. If your brain is telling you it’s foggy, it is foggy. The fix is not “one more prompt.” The fix is the same as it has always been: sleep, movement, real food, real people, real rest. Choose which trips are worth taking. This might be the most important one. Not every meeting requires a transatlantic flight. Not every task requires four parallel agents. The question worth asking, every time, is: does the speed I’m gaining here justify the lag I’ll pay later? Sometimes the honest answer is yes. A lot of times — more than we’d like to admit — it’s no. The Future Is Faster Than Today There is no version of the next decade in which we slow down. The pace of AI is not going back into the bottle, any more than commercial aviation was going to retreat to ocean liners. The future is faster than today, and the day after that will be faster still. Which means the question isn’t whether to engage. It’s whether to engage deliberately — with eyes open about what we’re trading and what we’re protecting. The frequent flyers who thrive over a long career aren’t the ones who pretend jet lag doesn’t exist. They’re the ones who respect it, plan around it, and build the recovery into the trip itself. They treat their bodies as the irreplaceable instrument that makes the whole career possible. We need to do the same thing with our minds. Because the alternative isn’t keeping up. The alternative is becoming the cautionary tale — the high-achiever who could have done anything, and instead did everything, until there was nothing left. The jet age didn’t make us superhuman. It made us travelers who had to learn new rules. The AI age is the same. Let’s learn the rules a little faster this time.