How do we do things without consciously being aware we are doing it?

Question

For example we might be sitting reading something and then suddenly realize we were playing with a pen without having any active thought to play with that pen.

Or perhaps you might be doing something weird with your tongue whilst focusing hard on a task, or playing with your beard whilst watching a video, etc etc.

How do we do these things without putting any active thought into doing it and why?

In: Biology

Answer 1

It becomes a habit.

When you do something without thinking about it, the same thought process that you go through when you do think about it still happens subconsciously.