Imagine our brain as a super-duper computer: it takes in information, processes it, and spits out a decision. Easy-peasy, right? Well, this is what we call the computer metaphor for the human mind.

But hold on a second! This metaphor has a BIG flaw. It assumes we are perfectly rational, always processing information logically and accurately. But we humans, as you probably know, can be wildly irrational sometimes.

Real-World Example It's like using a computer to write your English essay. The computer can spellcheck, sure, but it can't understand the deeper meanings behind words like humans can. So, you might end up with a technically perfect essay that doesn't really make sense or is dull as dishwater. The computer lacks our human quirks and nuances, just like the computer metaphor lacks understanding of our irrationality.

A guy named Freud disagreed with the computer metaphor. He knew our minds were a messy mix of rational and irrational.

In 1972, two psychologists named Amos Tversky and Daniel Kahneman introduced cognitive biases. Think of these as the "bugs in our system" - systematic ways we diverge from being rational. They found these "bugs" aren't occasional blips but happen all the time.

Real-World Example Ever thought you're more likely to win the lottery than to get struck by lightning? That's a cognitive bias! We tend to overestimate small probabilities and underestimate large ones. And guess what? Insurance companies LOVE this bias, because they can use it to sell you more insurance.