We all know our brains tend to play tricks on us sometimes. We can hallucinate, for example, or hear things that aren’t really there. But what about the more commonplace stuff that we can’t explain? There are the songs that get stuck in our heads and the words that suddenly lose meaning after being repeated several times. Well, here are some answers.

1.) Earworms

“Earworms” are what we call those songs that get stuck in your head on repeat. Notice that it’s never the entire song that repeats, though. It’s just a small section — maybe the chorus or a couple lines of the bridge that play on a continuous loop. Maybe you don’t even like the song, but you still find yourself stuck with it. At the same time, have you noticed that you probably don’t even know all the lyrics?

Scientists say that’s exactly why the song is stuck in your head. After singing the part you know, your brain tries to move on to the next section but can’t. Considering our brains love to return to unfinished thoughts, the song keeps returning to the part you know. Need help getting rid of the earworm? Researchers suggest reading a novel or solving anagrams — anything cognitive helps.

2.) GPS and its Effect on Us

Apparently, we rely on our GPS too much. We’ve gotten so used to using it that it’s become a crutch and we even use it to get around places that we’re already familiar with. This is because the GPS “lulls” us into a false sense of security. Our sense of direction even worsens, in fact.

We should only use the GPS when it’s truly necessary. Otherwise, we’re not exercising our spatial abilities, which researchers say could lead to early-onset dementia.

3.) Word Association

Take a word, like “zoo,” for example, and repeat it over and over and over again. It starts to sound funny, doesn’t it? In fact, the word starts to lose its meaning to you. It doesn’t sound like a word at all. It sounds like gibberish.

Scientists call this “semantic satiation.” That’s because normally when we say a word, our brains find the semantic information connected to that word. When you repeat the word over and over, though, your brain starts to have a harder time connecting the word with its semantic information.

4.) Sympathetic Pain

You know that feeling you get when you see or hear about someone else getting hurt and you wince as if it happened to you? Researchers call this sympathetic pain.

During a study, scientists used MRI machines to see how participants’ brains reacted when they saw certain expressions and made the same expressions. In both cases, the brain displayed the same activity. That’s because we have what scientists call “mirror neurons” in our brain that can create a sympathetic response. Basically, we’re wired to have the same feelings and emotions as other people.

5.) Imaginative Memory

We tend to trust our sense of memory, so when our memory department actually does fail us, our brain tries to fill in the gaps and tell us what we must have seen and heard.

This is why interrogation tactics and witness testimony can be so faulty. It’s very easy to plant fake memories in someone’s head with some leading questions. So the next time someone tries to pick your memory apart, maybe it’s better to say nothing at all.