All sorts of random thoughts and worries can occupy your attention when you want to get things done. An easy and effective way to avoid that is to write them down. You can write it on a paper or in a minimal note app. No need for complicated systems or perfect writing—the simpler, the better.
Don’t Ignore, Address
What you shouldn’t do—even though many people do it—is to ignore the thoughts. You won’t succeed in removing them from your attention. If you try to, you will end up in an awkward multitasking state. You won’t be able to focus on what you are doing because your attention is divided.
But this shouldn’t be viewed as a flaw of our brain. The fact that those thoughts are demanding your attention means that they are somewhat important, or at least worth thinking about. In any case, you should address them.
Address, But Not Now
But because you are occupied with some task at the moment, now is not the best time to do it. What can you do to make sure you will address them later? You have to hold it somewhere. How about holding them in your head? Not the best idea—memory is unreliable and you should try not to put extra burden on it. A better option is to write your thoughts down. This frees your brain as much as posssible.
One thing to be aware here is to avoid using complicated systems. A blank note is better than a full-fledged task database. The reason is that if you walk away too far, you need time to regain the focus you have built up. It’s no longer ideal if you need more than a minute to input everything. In this context, you need to log your thoughts as quick as possible. You can always transfer the content to a more powerful system later if you want to.
Memory Outside You
By moving the random distracting thoughts onto a note, you are using an external memory system. This means you don’t have to congest your brain anymore because you have somewhere else to congest. Your brainpower is limited but you can use something else to help them.
This concept of external memory system is often applied in situations where you need focus clarity. It’s highly effective.