We like to think of intelligence as something you can measure through grades, test scores, or maybe how quickly someone solves a problem at work.

But the truth is, some of the most telling signs of a deeply complex mind don’t look impressive at all on the surface. In fact, they can feel so ordinary that you wouldn’t give them a second thought.

I’ve spent years observing not only my own habits but also those of people I admire—mentors, friends, and even clients I used to coach back in my corporate days.

What I’ve noticed is that complexity doesn’t always announce itself loudly. It hides in the everyday. And often, the very things we brush off as “quirks” are the markers of a mind that works on more layers than most.

Here are seven everyday habits that might seem normal but actually point to a highly complex way of thinking.

1. Talking to yourself

Ever caught yourself mumbling while cooking or narrating your to-do list in the car?

At first glance, it seems like something kids do, or maybe a sign you’re stressed. But psychologists argue that self-talk is one of the clearest signs of advanced self-regulation and self-reflection.

Lev Vygotsky, a pioneer in developmental psychology, believed that talking to ourselves isn’t childish—it’s a sophisticated way to organize thought and behavior.

By voicing things out loud, you externalize what’s in your head and make it easier to structure and solve. Complex thinkers often rely on this because they have so many competing thoughts swirling around.

If you catch yourself talking to yourself more often than not, it’s not something to feel embarrassed about. It’s a habit that reveals you’re actively engaged in processing, directing, and regulating your inner world. That’s complexity in action.

2. Overanalyzing small details

People love to tease “overthinkers,” but the truth is, the ability to dissect small details is linked to what psychologists call cognitive complexity—a framework for understanding multiple perspectives and subtle differences.

Imagine noticing a friend’s tone shifting slightly during a casual chat, or picking up on the way someone rearranges their desk before a tough conversation.

A simple mind might dismiss these as irrelevant. A complex mind treats them as data points, building patterns and testing interpretations.

This is about having the mental horsepower to juggle layers of meaning at once. And while it can be exhausting (overthinking can definitely spiral), the same ability makes people great strategists, writers, leaders, and innovators.

I’ll admit, I’ve lost hours staring at a single paragraph I’m writing, trying to decide whether a word “feels” right. Annoying? Sometimes. But it’s also what creates depth in writing.

Details matter, and noticing them is a clue your mind runs deeper than average.

3. Constantly questioning “why”

Some people see constant questioning as skepticism or even stubbornness.

But at its core, asking “why” is an expression of deep curiosity and intellectual humility—the willingness to admit that what we know might not be the whole story.

Questioning is central to growth. When you ask “why,” you’re not just absorbing information passively—you’re actively reshaping your worldview. And the more layers you question, the more nuanced your thinking becomes.

Recently, I picked up Rudá Iandê’s new book Laughing in the Face of Chaos: A Politically Incorrect Shamanic Guide for Modern Life, and it challenged me to look at my own “why” questions differently.

One line in particular stuck with me: “Most of us don’t even know who we truly are. We wear masks so often, mold ourselves so thoroughly to fit societal expectations, that our real selves become a distant memory.”

That hit home because questioning “why” isn’t just about external systems—it’s about questioning ourselves. Why do we react a certain way? Why do we keep repeating the same patterns in relationships or work?

The book reminded me that our questions are less about finding neat answers and more about peeling back the masks we’ve been trained to wear.

If you find yourself constantly digging into the “why” behind things, take it as a sign you’re not just coasting through life—you’re actively reauthoring your story.

4. Daydreaming or zoning out

When was the last time you caught yourself staring at a wall, lost in thought? Most people chalk this up to distraction, but neuroscientists see it differently.

The brain’s default mode network (DMN)—the system activated when you’re not focused on a task—is linked to creativity, self-reflection, and long-term planning.

In other words, zoning out isn’t wasted time. It’s your brain running mental simulations, rehearsing scenarios, or connecting dots that don’t line up when you’re grinding on a spreadsheet.

I used to get in trouble for this at work. During meetings, I’d drift off, not because I wasn’t paying attention, but because my brain was working overtime on the implications of what was being said.

Later, those “zoned-out” moments would turn into fully formed strategies.

Einstein famously called imagination more important than knowledge. Daydreaming is your imagination at work. If you lean into it, you’ll often find the seeds of ideas that practical thinking alone can’t produce.

5. Taking longer to make decisions

Complex thinkers tend to delay decisions—not out of indecision, but because they’re running multiple simulations at once.

Psychologists call this counterfactual thinking—the ability to imagine “what if” scenarios and weigh them.

Research in cognitive psychology shows that people who engage in upward  counterfactual thinking often make more adaptive and creative choices.

The downside is it can look like procrastination. But in reality, it’s your brain doing quality control on the future.

Yes, it can be tiring, and sometimes you just need to choose. But don’t discount the value of thoroughness. The habit of taking your time shows your decisions aren’t knee-jerk—they’re calibrated.

6. Loving paradoxes and contradictions

Most people crave certainty. Complex minds, on the other hand, tend to be drawn to paradox. You might actually enjoy the tension of two opposing truths and feel energized by ambiguity.

Psychologists call this dialectical thinking—the ability to hold two contradictory perspectives and integrate them. It’s a trait linked to creativity, resilience, and even higher emotional intelligence.

Take relationships, for example. You can love someone deeply and still feel frustrated by them. You can crave independence but also need closeness.

A simple thinker sees this as confusion. A complex thinker sees it as the messy, beautiful reality of being human.

One of my college professors once said, “If you want clean lines, study math. If you want meaning, study people.” I think about that a lot. A complex mind doesn’t force everything into neat boxes—it allows space for contradiction to coexist.

7. Collecting random facts or interests

Have you ever gone down a rabbit hole about ancient history, chess strategies, or why bees communicate through dance—and then wondered if you’re just wasting time?

Well, you’re not. This is known as divergent thinking—the ability to connect seemingly unrelated fields of knowledge.

Complex minds love to gather raw material. Random facts become building blocks for analogies, problem-solving, and creativity. That’s why people who seem “scatterbrained” with hobbies often end up being the most innovative thinkers.

For instance, I went through a phase where I devoured books on behavioral economics, even though my job at the time had nothing to do with it. Years later, those concepts helped me write better about relationships and decision-making.

Steve Jobs famously showed how a calligraphy class he took in college later influenced the elegant design of Apple’s fonts and user interfaces. You never know when a random piece of knowledge will unlock a new perspective.

So if your interests seem “all over the place,” embrace it. Complexity thrives on diversity, and your curiosity is a mirror of your mind’s depth.

Final thoughts

The habits on this list aren’t flashy. You won’t win awards for talking to yourself in the car or zoning out in a meeting. But they reveal a mind that doesn’t settle for surface-level.

Complexity shows itself in the way you notice, question, connect, and simulate. And while these habits can feel inconvenient or even misunderstood by others, they’re signs of a brain that sees more, feels more, and integrates more than most.

So the next time you catch yourself overanalyzing, questioning, or drifting off into a daydream, remind yourself: you’re not odd—you’re operating on a richer wavelength.