When the World Feels Distant: The Unseen Link Between Physical Fatigue and Our Evolutionary Past

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Have you found yourself less eager to meet people lately, or feeling strangely indifferent toward those around you?

Maybe you used to be cheerful and optimistic, but lately you’ve wondered whether you’re simply growing more mature—or slowly drifting away from the world.

If that sounds familiar, understanding physical fatigue might offer a little comfort, and perhaps even an answer.

Here’s the short version: when we’re physically exhausted, our bodies prioritize recovery, leaving us with less energy to devote to social interactions. 😲

When Physical Fatigue Caught Up with Me

Fatigue comes in different forms. I’ve written before about central nervous system (CNS) fatigue and mental fatigue, haven’t I?

To be honest, I’d rarely experienced physical exhaustion so severe that I failed to recognize it for what it was.

Recently, however, my body was losing water weight while I kept lifting the same heavy weights—and even increasing them. Without realizing it, I was accumulating deep physical fatigue.

In fact, I recently lost around 11 kg, bringing my weight down to 75–76 kg. It wasn’t simply a loss of muscle mass; much of that change appeared to come from a reduction in body water.

I’d previously lost about 5 kg after cutting back on food delivery and switching to home-cooked meals. If you’re curious about that earlier experience, take a look at The Remarkable Changes I Experienced After Giving Up Food Delivery as well. 😊

The Profound Shift After Letting Go of Delivery Meals: Losing 5kg and the Miracle of Serene Energy

Even though my body had changed so much, I was still lifting the same heavy weights—and gradually setting new personal records.

As my body lost water, the cushioning that absorbs the impact of the barbell diminished, making each lift far more demanding. All the while, my body was quietly bearing that enormous load. 🙂

But there was something else that made this especially interesting.

Because I’d been consistently going to bed early and waking up on time, I found myself completely free of the CNS and mental fatigue I was used to, with an unusually clear head.

With my mind clear and my motivation intact, I’d think, “I feel pretty good today,” then naturally head out, stay active, and keep training.

But my body—right down to its cells—was already running on empty. My mind was ready to keep going, while my physical energy was almost gone. That strange mismatch left me feeling unusually numb and less responsive in my interactions with others.

I’d been through something similar before: I kept exercising without giving my body enough fuel. I wrote about that experience and the importance of nutrition in Even Workouts Need Fuel. 😉

Exercise Needs Fuel Too – Overcoming Lethargy and the Moment Your Body Comes Alive

For a while, I wondered whether I was simply becoming less concerned about other people because work was going well and life had become more comfortable. Sometimes I even asked myself, “Am I heading in the wrong direction? Has my personality changed?”

I’ve loved talking with people and valued relationships since I was young. If even I could feel so confused, how were others coping with this kind of exhaustion? Maybe they’d been pulling away from people without even noticing. 🥲

Why Does Physical Fatigue Make Us Want to Withdraw?
(An Evolutionary Psychology Perspective)

It may have something to do with the brain’s “energy-saving mode” at work.

We can look at fatigue in three ways.

• CNS Fatigue (Central Nervous System Fatigue): When the nervous system is overloaded, a person may become more sensitive and feel as though their surroundings are threatening.
• Mental Fatigue: The fogginess that can follow prolonged intellectual work or hours in front of a screen, when thoughts no longer flow easily.
• Physical Fatigue (The Focus Here): A state of deep exhaustion in the muscles and connective tissues following intense activity or significant energy depletion.

When physical fatigue builds up, the brain can seem to turn down its “social interaction switch.”

Social connection can be wonderfully restorative—but it helps to have some energy left in the tank. Reading someone’s facial expressions, tuning in to their emotions, and choosing the right words all require cognitive effort, powered by the brain’s use of glucose and oxygen. 😳

Put simply,
You need a vessel before you can fill it with water.

Looking at this through the lens of evolutionary psychology makes the idea even more interesting.

Imagine our hunter-gatherer ancestors, utterly exhausted from hunting or injured, spending their remaining energy on status conflicts or lengthy conversations. What might that have meant for their ability to recover and survive?

From an evolutionary perspective, conserving energy and focusing on recovery during periods of extreme fatigue may have offered a survival advantage. It’s almost as though the brain were whispering, “This isn’t the time to socialize. Find a quiet cave and let your body recover first.”

Seen this way, the desire to withdraw may not be a flaw in our personality, but a kind of protective barrier our bodies put up when we need rest. 🙂

Have you ever noticed, though, that even when you’re exhausted, there are certain people you can still feel completely at ease with?

Perhaps that’s because, in relationships built on deep trust and a sense of safety, we spend less energy worrying about how we’re perceived or staying on guard. Even when we’re physically drained, it can feel easier to relax around those people.

Me at the Jiu-Jitsu Gym

Recently, after recovering from an injury, I returned to Paraestra for Brazilian jiu-jitsu for the first time in a while.

I still hadn’t fully recovered physically, but thanks to the strength I’d built over time, I made it through training with the same intense concentration as usual.

Maybe this was another example of something I’ve written about before: growth that raises even your lowest point.

Despite being physically exhausted, the strength and sleep habits I’d built helped me keep going. I wrote more about this idea in My Life Is a Google Dance. 😄

My Life Is a Google Dance

Yet throughout training, I found myself becoming unusually preoccupied with the people around me.

I could recognize CNS fatigue fairly quickly because I knew what it felt like. But this kind of purely physical fatigue was unfamiliar, so I struggled with thoughts like, “Why can’t I read people’s emotions properly? Do they dislike me?”

The strange thing was that I felt completely at ease with my instructors and the people I knew well.

All I needed to do was listen to them; I wasn’t wasting energy on that awkward sense of self-protection. Perhaps it was because the trust we’d built made those relationships feel like a safe place.

The Truth Behind the Misunderstanding: “Do They Dislike Me?”

I could relax around people I trusted, yet felt numb in crowded or unfamiliar settings. Looking back, the simplest explanation was that my body’s battery was at 0%.

When we avoid people, we sometimes blame ourselves: “Have I become cold?” Or we see someone’s blank expression and wonder, “Do they dislike me?” We turn a moment of exhaustion into a question about character or relationships.

But what matters is recognizing what our brains might be telling us in that moment.

“Right now, you don’t have the energy to read everyone else’s expressions or attend to their feelings.
Let your body recover first.”

Once I understood that, I could look at myself with the same gentle understanding I used to have.

People who seemed especially cold, the expressionless bus driver who’d spent all day behind the wheel, the silences I might once have interpreted as unfriendly—I began to see them differently. Maybe some of those moments were simply the quiet signs of bodies worn out by people doing their best to get through the day.

Perhaps they didn’t dislike me at all. Perhaps they were just catching their breath.

Come to think of it, I’d had a similar realization before.
After a phone call with a customer service representative left me feeling hurt, imagining what their day might have been like softened my heart. I’d also love to share that story of moving from hurt feelings to understanding with you. 💜

I Was Angry at the Agent… Then Something Shifted (From Emotion to Understanding, and the Brief Afterglow)

Do You Feel Like Stepping Away from the World Right Now?

If you’ve been wanting more time alone lately, or meeting people feels exhausting, please don’t be too hard on yourself. It doesn’t mean you’ve become a cold person or that you’ve lost your connection to the world forever. 😊

Maybe your body has simply been working so hard to get through each day that it’s asking you to turn down the social noise for a little while and rest.

Rather than forcing yourself to act cheerful and socialize, it may be more important to quietly listen to what your body is telling you.

Just as you need a vessel to hold water,

our own bodies need to be replenished before the kindness within us can naturally overflow toward others.

What You May Need Right Now

1. Enough nourishing food and water to replenish your body
2. Time to set aside the weight of your daily responsibilities
3. Deep, unhurried rest—even a weekend spent curled up in bed, catching up on sleep

As your energy returns, the door to your heart may quietly begin to open again.

Everyone carries a light of their own.

Thank you for reading. 🩷