We should be aware of our surroundings. We should be able to assess our surroundings and make predictions about what we should be doing.
Just as important is being able to make good predictions about what is going to happen, and what we should do. So when a man in an alley makes a good prediction about what he is going to do, he is not being delusional. He is using his knowledge of the world to predict what he is going to do.
Even a man who is not a paranoid schizophrenic is aware of possible dangers, and he is aware of what he should do to prevent those dangers from happening. A person who is paranoid schizophrenic is not aware of the danger and therefore does not have the knowledge necessary to make good predictions. But a person who is not paranoid schizophrenic is aware that the world around him is dangerous and yet he is not aware of what he needs to do to be safe.
Even though a paranoid schizophrenic is aware that the world is dangerous, he still does not have the knowledge to prevent bad things from happening. He would never think the way a paranoid schizophrenic does about bad things happening. But a person who is not paranoid schizophrenic is aware that bad things are happening, and therefore he does have the knowledge necessary to figure out how to protect himself.