The Brain in Perspective

I was watching a show last night on Science Channel that dealt with mental illness.  The program went through the stories of four people who had different types of disorders that skewed their individual realities.  The disorders varied from memory loss to outright delusion.  There was a woman who saw a picture of her husband, recognized him in the picture, but did not recognize him in person.  Further, she accused him of taking her husband and being a double of him as part of a conspiracy. There's the man who see the world as everybody else, but does not recognize objects or people (not even a photograph of himself).  He stands in front of a bin full of bananas and asks, "where are the bananas?"  His daughter passes by, walks right next to him, sit down by him and he doesn't know who she is until she speaks.  His disorder was caused by an auto accident and it left him with a huge gap in memory.  He recognizes pictures of his daughter from the years before his accident.  Another side effect of this disorder is that he does not form an emotional bond with anything or anyone. There was another man whose brain filled in the gaps in memory with delusional imagery.  He saw a picture of a woman, but he saw two large, black orbs instead of her eyes.  Some people call him blind, but his eyes are functional, the part of his brain that translates visual signals is damaged. I cannot remember the other person or his/her disorder at the moment, but the program was very fascinating.  Unfortunately, it is quite difficult to grasp the concept of what there people are going through and makes it difficult to really understand.  People with "normal" minds and brains are used to seeing things "normally."  We have no concept of delusion or what it would be like to look at a parent, spouse or sibling and not know who they are.  What are your thoughts on this?