to this:

At work, an employee passes by and talks to himself.
Employee, me :"What a nightmare, he talks to himself!"
The nightmare is not that he talks to himself, but that he disputes with himself.

Maybe the split of the personality, or maybe it is more convenient for him to weigh the pros and cons. Some by this method the paper is scratched and printed. Text is better perceived, some sound is better absorbed. There are no normal, there are no examined.