Our brains are pretty amazing, but they can make a lot of mistakes that we are not even aware of. Sometimes these may have negative long-term consequences, but often they just mean a moment of misunderstanding or confusion. Here are 5 common mistakes your brain makes every day!

1. We trust our memories, even though they are often wrong. 

Eyewitness accounts used to be the gold standard of criminal trials – until their veracity and accuracy was widely disproven by experts and scientists. It’s not that the witnesses were lying; they truly believed what they had “seen” even when it was wildly different from anything they could possibly have witnessed. That is just one example of our imperfect memories, and there are many others. Yet time and time again, we tend to trust our memories and ignore the fact that they are susceptible to mistakes and biases.

2. We let our expectations decide what we’re experiencing.

We all have “mental maps” in our brains that tell us what to expect, and we often let them rule us even when we know they are wrong. A good way to illustrate this is by using optical illusions that prey on our expectations. For example, Adelson’s Illusion uses our expectation of light and shadow to make our brains “see” colors differently, while the Reversed Face Illusion uses our expectation of facial structure to “see” upside-down faces as normal even when they are grotesquely altered. Regardless of what the real world actually shows us, our brains rely heavily on what we expect to be shown when making judgments and decisions.

3. We feel losses more strongly than gains – which can lead to poor decision-making.

Psychologists have described and tested people to determine that most of us are susceptible to the “sunk cost fallacy” as a way to describe how humans feel losses more strongly than gains, and how it can affect our decisions. In this case, a “sunk cost” refers to money, time, or effort that has already been used and cannot be recovered. Oddly enough, many of us allow these unrecoverable past “costs” to guide our decisions in the future, which makes no logical sense.

For example, imagine you are at the movies and you really hate the movie, but decide to stay because you’ve already paid for the ticket. That’s allowing the sunk cost fallacy to irrationally guide your decisions, when logically it would make more sense to leave the movie theater so you can do something you enjoy more.

4. We are highly prone to stereotyping people, even when we consciously try not to. 

It doesn’t matter how hard we try not to pay attention to stereotypes–our brains are strongly influenced by them even when we actively try to ignore or negate them.

There is a classic psychology experiment from the 1980s that makes this point quite clear. Researchers asked people to read a description of a person, which said “Linda is thirty-one years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in antinuclear demonstrations.” Then they asked the people to say whether they thought it was more probable that a) Linda is a bank teller or, that b) Linda is a bank teller who is active in the feminist movement. 85% of participants chose B, even though that is not the logical answer, because if B is correct than A is also correct. Ergo, A is the more probable statement. But people’s brains couldn’t help applying the stereotype to Linda’s description even when it flew in the face of logical reasoning.

 5. We are not great at predicting odds and probabilities, but we don’t realize it. 

Let’s say you flip a coin 3 times and it comes up “heads” every time. Surely the next flip must be “tails” – right? Wrong: it doesn’t matter if you flip the coin and it comes up “heads” 3 times, 30 times, or 300 times; the odds of each coin flip will always be 50/50, regardless of the previous flips. This is known as the “gambler’s fallacy” and occurs because we take a random event like coin flipping and try to apply a different and incorrect kind of pattern-based logic to the event.