Valeriia Leykin's Key Ideas from The Little Book of Stupidity
by Sia Mohajer

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A brain bias is a built-in shortcut your mind uses to process information faster. While this saves energy, it also leads to predictable thinking errors. The brain takes mental leaps instead of thinking everything through—sometimes it works, sometimes it fails spectacularly.

3️⃣ 🔹This illusion of confidence actually starts in childhood when parents praise everything we do, even if we do it wrong. As kids, we internalize this feeling of competence, and if not challenged, it follows us into adulthood.

🔹 Even grown-ups fall for the Dunning-Kruger effect—believing they know more than they do. That’s why people argue passionately about things they barely understand. This confidence makes us blind to our own ignorance.

4️⃣ Your brain hates being wrong, so it filters reality to support your existing beliefs. This is why:

✅ You only notice news that confirms your opinions.

✅ You remember things that support your views but forget things that don’t.

✅ You reject facts that challenge your perspective, no matter how logical they are.

🔹 Confirmation bias is why debating rarely changes minds—people don’t seek truth, they seek validation.

5️⃣ Your brain latches onto the first piece of information it sees and compares everything else to it. That’s why stores show ridiculously high "original prices" before giving you a "huge discount"—even if the discount isn’t real, your brain sees it as a great deal. This is why negotiators, marketers, and salespeople use anchoring to manipulate decisions

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6️⃣ Your brain judges risks based on what comes to mind first, not what’s actually dangerous.

📌 People fear plane crashes more than car accidents, even though cars are statistically far deadlier. Why? Because plane crashes are dramatic, newsworthy, and memorable, while car crashes happen daily but don’t make headlines.

7️⃣ Biases exist because the brain hates wasting energy. Instead of analyzing every situation from scratch, it takes mental shortcuts. Most of the time, these shortcuts work well—they help us react fast and make quick decisions. But when they fail, they lead to stupid mistakes. Understanding your biases helps you control them, instead of letting them control you.

8️⃣ It's not easy to spot biases in others while thinking we’re completely rational. But here’s the truth: we all fall for the same mental traps.

🔹 That’s why self-awareness is crucial. If you understand how your own brain tricks you, you’ll be much better at spotting flaws in your own thinking before judging others.