People talk to themselves far more often than they usually admit.
You may say:
“Keys, wallet, phone.”
Or:
“Okay, first I need to move this.”
That kind of ordinary self-talk can help organize thinking.
Language can help structure a task
A complicated job contains several steps.
Saying those steps out loud can turn a vague problem into a sequence.
Instead of holding everything in mind at once, you can give yourself one instruction at a time.
That can make planning easier.
Self-talk can support memory
Spoken words give information another form.
You are not only thinking the instruction.
You are also hearing it.
That can make a short sequence easier to hold onto while you act.
This is why someone may repeat a short list aloud while walking from one room to another.
Of course, that same working-memory system can still fail, which helps explain why you can walk into a room and forget why you went there.
Children do it openly
Children often talk themselves through tasks out loud.
Adults tend to move much of that speech inward.
The process becomes internal thought.
But adults still use spoken self-talk when concentrating, planning, remembering, or solving something difficult.
Why does saying it aloud sometimes help?
A spoken instruction can make the next action more concrete.
It also keeps attention attached to the task.
If your mind begins wandering, the words can pull focus back toward what you are trying to do.
Is talking to yourself unusual?
Ordinary self-talk is extremely common.
The content and circumstances matter, but simply talking out loud while planning or concentrating is not strange by itself.
People use language socially.
They also use it as a tool for their own thinking.
Is self-talk always helpful?
Not necessarily.
Repeating unhelpful or negative thoughts can also shape attention.
The useful version is the kind that organizes information, clarifies the next step, or helps maintain focus.
Sometimes saying the thought out loud simply makes it easier to work with.
Apparently your brain does not object to being both the speaker and the audience.
And that’s the short explanation.
Related explanations: Why do unfinished tasks stay in your mind?, Why do we procrastinate?, and Why do we walk into a room and forget why?