When healthy people interpret a situation it's based on their memory of similar situations in the past, what they did and how other people responded to what they did. These are known as situational cues.

As you can see in the diagram, the way a person responds to a vague instruction depends on their memory of other similar situations in the past. They first interpret this situational cue. They formulate appropriate goals to the cues given. This leads to a response, in this case washing their face. Finally, the person is able to use further cues to evaluate the response.