Some people walk around convinced they’re the smartest person in the room, when in reality, they’re missing the mark completely.

They talk like they have all the answers, dismiss other people’s opinions, and act like they’re always two steps ahead. However, when you really pay attention, it becomes clear that they’re not as sharp as they think (and want everyone else to think, too). Whether it’s overconfidence, a lack of self-awareness, or an unwillingness to learn, certain things they do make it clear they haven’t got a clue.
1. They talk a whole lot, but don’t do much listening.

Truly intelligent people ask questions, listen to different perspectives, and take the time to absorb information before speaking. However, people who only think they’re brilliant tend to dominate conversations. They love to hear themselves talk, rarely let anyone else get a word in, and assume that their opinion is the only one that matters. The irony is that the more they talk, the more obvious it becomes that they don’t actually know as much as they think.
2. They dismiss other people’s ideas too quickly.

People who believe they’re geniuses often struggle to consider the possibility that someone else might have a good idea. Instead of engaging in thoughtful discussion, they immediately shut down viewpoints that don’t match their own. Rather than asking, “Could I be wrong?” or “What can I learn from this?”, they assume that if they didn’t think of it, it must be nonsense. It not only makes them seem clueless, but also stops them from ever actually learning anything new.
3. They mistake confidence for intelligence.

Some people believe that if they say something loudly and with enough conviction, it automatically makes them right. The truth is, confidence and intelligence aren’t the same thing. Truly smart people don’t need to shout people down or act like they know everything. Those who only think they’re brilliant, however, rely on their forceful delivery to cover up the fact that they don’t actually have the depth to back it up.
4. They throw around big words to sound smart.

Using complicated words and jargon might make someone sound intelligent at first, but if they’re just using them to impress rather than communicate, it quickly becomes obvious. People who are actually smart can explain things in simple, clear terms. People who just want to seem smart, on the other hand, often overcomplicate things to cover up the fact that they don’t actually understand what they’re talking about.
5. They pretend to know things they clearly don’t.

Instead of admitting when they don’t know something, these people will confidently make things up, fake their way through a topic, or try to bluff their way into sounding knowledgeable. Of course, real intelligence isn’t about knowing everything; it’s about being curious and open to learning. The smartest people aren’t afraid to say, “I don’t know” and find out the answer.
6. They always have to “win” every discussion.

Debating and discussing ideas can be a great way to learn and grow, but people who think they’re brilliant often see every conversation as a battle that they have to win. Instead of engaging in an actual exchange of ideas, they focus on proving themselves right, even if it means twisting facts, ignoring key points, or resorting to personal attacks.
7. They don’t admit when they’re wrong.

No one likes being wrong, but truly intelligent people know that mistakes are part of learning. Those who just think they’re smart, though, will go to great lengths to avoid admitting when they’ve made a mistake. They might deflect blame, change the subject, or twist the argument to make it seem like they were right all along. But refusing to acknowledge mistakes doesn’t make someone look smart—it makes them look insecure.
8. They assume their opinion is always fact.

People who overestimate their intelligence tend to confuse their opinions with universal truths. They’ll confidently state their personal preferences as if they’re objective facts, dismissing anyone who disagrees. However, real intelligence involves understanding that different perspectives exist—and that just because you believe something doesn’t mean it’s automatically correct.
9. They try to impress rather than understand.

Some people enter conversations not to learn, but to show off. Instead of engaging with what’s being said, they spend their time looking for opportunities to insert their own knowledge (or what they think is knowledge). They care more about sounding smart than actually expanding their understanding, which ironically makes them seem less intelligent over time.
10. They name-drop or mention credentials constantly.

Ever met someone who constantly reminds you of their qualifications, job title, or who they know? People who are truly intelligent don’t feel the need to prove it with constant name-dropping. Those who are insecure about their intelligence, however, often lean on these things to try to convince other people that they’re brilliant, even when their words and actions suggest otherwise.
11. They assume intelligence is fixed.

One major difference between truly intelligent people and those who only think they are is mindset. Smart people know that intelligence is something you can develop over time. People who are clueless often believe they were just “born smart,” which leads them to avoid challenges or new learning experiences that could expose their weaknesses.
12. They underestimate people.

Instead of respecting different forms of intelligence, people who overestimate themselves tend to assume that if someone thinks differently from them, that person must be wrong or less capable. But intelligence comes in many forms—creativity, emotional intelligence, problem-solving, and more. Underestimating people doesn’t make someone smarter; it just makes them narrow-minded.
13. They refuse to accept or even listen to feedback.

Genuinely clever people welcome constructive criticism because they know it helps them grow. However, those who just think they’re brilliant often react poorly to feedback, seeing it as an attack rather than an opportunity to improve. Instead of listening and considering what’s being said, they get defensive, dismiss the person offering feedback, or try to argue their way out of it.
14. They don’t realise how much they don’t know.

Perhaps the biggest giveaway that someone isn’t as smart as they think? They have no idea how much they still have to learn. Truly intelligent people understand that knowledge is endless; they’re always learning, questioning, and staying open to new perspectives. Those who believe they already know everything, on the other hand, are usually the ones who have the most to learn.