79 | Why Do I Have Brain Fog, and What Screen Time Has to Do With It

If you have been asking yourself why do I have brain fog, you might want to consider your screen time. For a lot of us, that foggy, scattered feeling, and the sense that our memory is worse than it used to be, traces back to something surprisingly simple: how much we have quietly handed over to our phones.

Can you tell me your best friend’s phone number right now, without looking at your phone? What about your child’s number?

If that made you pause, it should.

How Screen Time Feeds Brain Fog

Not that long ago, you probably knew a dozen phone numbers by heart. You knew the route to your best friend’s house without a map. You could recite your grocery list because you had rehearsed it in your head before you even left the driveway. None of that took extra effort. It was simply how your brain worked, because your brain had to work that way.

Somewhere along the line, your phone quietly took over that job.

Now nobody is asking you to throw away your calendar app and start carving dates into stone tablets but memory is not just storage the way a filing cabinet is storage. Memory is a muscle and muscles that stop being used get weaker.

When we hand every act of remembering over to a device, we are not just saving ourselves a little effort. We are letting a real skill atrophy. If your memory feels worse than it used to lately, this is often a big part of why. A 2025 review of research on heavy digital reliance found a growing body of scholarship connecting frequent offloading of information onto devices with attention and memory concerns, even though researchers note more long-term data is still needed. In plain terms, the less you ask your brain to hold onto, the rustier that muscle gets, and that rustiness is exactly what shows up as brain fog.

What Scripture Says About Carrying Truth in Your Mind

In Deuteronomy 6, God tells His people to take His words and impress them on their hearts, and to talk about them when they sit at home, when they walk along the road, when they lie down, and when they get up.

That passage is not about phone numbers. But it is about the discipline of carrying something in your mind on purpose, rather than letting it sit outside of you in a book or on a screen. There is something formative about holding truth inside you instead of only being able to access it when you look it up.

A Simple Way to Start Clearing the Fog

Pick one small thing you would normally look up, and hold it in your mind instead.

Choose an important number of a friend, spouse, or child and memorize it. You never know when you might need it. A dead battery, a lost phone, an emergency where someone else has to make that call for you. It is a small, practical act, and it also happens to retrain a muscle you may not have used in a while.

Take It Deeper

If this hit close to home, brain fog is often just one symptom of a much bigger pattern of digital overwhelm. My workshop, Focus Modes Made Simple, walks you through practical steps to reclaim your attention so your brain has room to actually think again. You might also enjoy a dopamine detox or the screen time personality quiz to see where your own habits stand.

And if you have not already, listen to Episode 68 on task switching for more on how constant device checking fragments your focus and memory.

FAQ

Why do I have brain fog all of a sudden?

Sudden brain fog can have many causes, including sleep, stress, and diet, but one often overlooked factor is how much mental work you have handed over to your phone. When you stop rehearsing information in your own mind, the mental muscle that supports sharp thinking gets less exercise.

Why is my memory so bad lately?

If your memory feels worse than it used to, take an honest look at how often you look things up instead of trying to recall them first. Small daily habits, like checking a calendar app instead of remembering an appointment, add up over time.

Can I improve my memory without giving up my phone?

Yes. Start small. Choose one piece of information you would normally look up, such as a phone number, an address, or a short list, and commit it to memory instead. This is not about rejecting technology, it is about giving your brain regular reps.