Expectation Effect

This happen when I was studying in an University oversea, once someone was driving me to visit a mental hospital out of curiosity (which I heard was the biggest in the States). We was permitted in the visit area where they allowed some mental patients of least severe affliction. This time, however, we are out of luck since we don’t have any patient there. All is gone expect one.
We are all excited to see a real mental patient. However, that strike me as an odd as that patient looks absolutely normal in every aspect of his behavior(And he is pretty good looking also). Try as I might, I really can’t tell what is wrong with him. So the conclusion I drawn is that he must be a patient almost completely recovered from his disorder, since they are very selective in whom is allowed in the visitation area. You know, it is really hard to distinguish a mental patient just by sight.(I was told that many of them are addicted smokers.)
Imagine the shock I had when we meet him on the road: He is driving there for the same purpose as us! He was also curious in finding out what mental patient is like. Then it appears in my mind that would he also be shocked when he discover that we are also NOT mental patients? It is because we are inside a mental hospital therefore we expect everyone beside the worker there to be mental patient. The situation that we are inside a mental hospital has primed the connections between mental hospital and mental patient in the schema, therefore we see what we expect. We expect a mental patient in a mental hospital, thus we see everyone as mentally disordered. This is the very idea of Expectation Effect in Cognitive Psychology.