She didn’t shout when she climbed out of the pool, but her words still hit her mom like a lightning bolt.

I (L. E.) wasn’t trying to listen in on what was clearly a private conversation, but there’s never a lot of room when you’re lining up for your heat at a swim meet. It’s always an awkward collection of wet kids jammed together under pop-up tents.

I was on the swim team when I was in high school, and my summer days were often spent on the side of a pool waiting for my race to start. I didn’t know the swimmer who brushed by me that day, but it was impossible to miss what she said.

Covered in chlorine and disappointment, she locked eyes briefly with her mom and then proclaimed to no one and everyone, “I suck at swimming. I’m the slowest swimmer ever. I’m the worst person on the team.” Then she trudged away to reluctantly get ready for her next race.

Her mother was speechless, perhaps all too familiar with statements like this. But I couldn’t help having my own opposite reaction to the scene. “Those are just broken soundtracks. She can change that,” I thought to myself.

That idea quickly jumped into my head because for years my dad and my little sister McRae have talked about exactly that. It can always be a little awkward when you change narrators in a book, so I’ll keep this brief. My name is L. E., I’m 19 years old and I attend Samford University in Birmingham, AL.

Some people describe thoughts as leaves on a river, clouds in the sky or cars on the highway, but at our house we always call them soundtracks. That word is a fun way to think about your thoughts because a soundtrack is one of those things that often plays in the background. You might not even notice it, but it has the power to change the entire moment.

Think about what music does to a simple TikTok video. At the time we were writing this, one popular meme involved placing a line from a Sam Smith song that says “By the way, she’s safe with me” onto a video of your boyfriend, girlfriend or even your dog. It was meant to change a simple clip of someone walking down the beach into a statement piece essentially saying, “You hurt this person in the past, but now she’s safe with me.” A single lyric changes the mood from a casual video into a complex, emotionally charged, baggage-heavy scene about rescue and redemption. That’s just one example. It feels like half of going viral on TikTok is finding the right song or sound.

Soundtracks change EVERYTHING, and that’s how your thoughts work too.

The loudest thoughts you have—the ones you might have listened to for years—never just stay thoughts. They always turn into actions, and those actions turn into results.

If you tell yourself a thousand times that you won’t make the soccer team, guess what happens? You don’t try out for the soccer team. If you don’t try out, guess what result you get? You don’t make the soccer team. Your thought turned into an action that turned into a result.

This isn’t something that happens only to high school students. Scientists have been studying it for years. The craziest example happened at New York University. Researchers there did a study to see how powerful thoughts can be. They brought two groups of college students into a room and asked them to make sentences out of a word bank, which is just a random collection of words on a piece of paper.

Both groups made as many sentences as they could, but there was something slightly different about the words the second group of students was given. Hidden in that word bank were ideas related to old age. Words such as bald, Florida and wrinkle were sprinkled throughout their set. You know your state is full of old people when it’s used as an example in a scientific study!

At the end of the word challenge, the scientists told the students to walk down the hall to complete the second portion of the study in another classroom. As they made their way down the hall, the real test began. The scientists secretly timed the students to see how long it took them to make the short trip. The students exposed to the set of old-age words walked slower.

Just reading the words about being elderly caused a physical change!

That’s wild, but it makes sense when you think about it. A friend who says something mean to you first thing in the morning can ruin your whole day as you replay that conversation in your head. An exam you’re dreading on Monday can reshape your whole weekend. A date you’re looking forward to can make your entire week feel bright and hopeful.

Your thoughts are the internal soundtracks you listen to, and they impact every part of your life. The longer you listen to a certain thought, the more it becomes part of your personal playlist.

That wasn’t the first time the frustrated swimmer had thought, “I’m the slowest swimmer on the team.” It was probably the thousandth time. She had listened to that soundtrack so often that if she was off her race time by even a fraction of a second, it would play automatically.

That’s how our brains work. The fancy term is cognitive bias, but it basically means that your brain likes to believe what it already believes. It’s biased to believe old soundtracks. So, if you believe you’re a slow swimmer, it will look for proof of that. It will collect evidence to back that up, like a lawyer preparing for a court case against you. Your brain is kind of a jerk that way.

Your soundtracks playing automatically wouldn’t be such a bad thing though—if they were positive. Who wouldn’t want positive thoughts playing in their head all day?

• “You’re going to make the football team!”
• “People like you!”
• “You get invited to all the fun parties!”
• “You got this!”
• “You’re definitely capable of passing that class!”
• “It’s OK that you don’t have it all figured out. Nobody does at your age!”

That would be amazing but raise your hand if that’s what all your soundtracks sound like. Most of mine certainly don’t, and you and I aren’t the only ones. I know firsthand how negative soundtracks sound because I’ve read through hundreds of them in those boxes of anonymous notes from students.

I wish I could say they were encouraging like the ones I listed above, but that would be a lie. Instead, they said things like this:

• “None of your friends really like you. They’re just being nice.”
• “You’re not skinny enough, despite how much you work out.”
• “You’re worthless.”
• “You will fail your future family because your parents failed theirs.”
• “Don’t break up with him, because no one else wants you.”
• “Your troubles with your mom are all your fault.”

Those are broken soundtracks, repetitive thoughts that make life harder, not easier. But how do you know if you have one? If the first step to tapping into the superpower of mindset is to retire your broken soundtracks, how do you even identify one?

for further study

Read:

• Your New Playlist by Jon Acuff, L.E. Acuff and McRae Acuff
• Soundtracks: The Surprising Solution to Overthinking by Jon Acuff 
• We’re All Freaking Out (And Why We Don’t Have To) by David Marvin 
• Get Out Of Your Head by Jennie Allen 
• Mental Health Moments | Peer Magazine

Used by permission from Baker Books, a division of Baker Publishing Group. Originally printed in Your New Playlist by Jon Acuff, L.E. Acuff and McRae Acuff.