The phenomenon of the occurs when an individual confuses her own thoughts with those of a hypothesized group of people.

The answer to this question is  imaginary audience
In general, before we tried to engage to other people, we will tried to first create a mental simulation on how people will respond to our words. By doing this, we create the imaginary audience. This phenomenon doesn't necessarily a good thing to do because there are too many factors that could influence people's behavior.