This reminds of a fascinating book, The Man Who Mistook His Wife for a Hat by Oliver Sacks.
One of the most interesting stories is about a man who lost his ability to intuitively recognize things and needs to reason about their features to find out what they are.
This is my shoe, no?
No, it is not. That is your foot. There is your shoe.
Ah! I thought that was my foot.
Currently reading Hallucinations. His coverage of such bizarre conditions as Akinetopsia (http://en.wikipedia.org/wiki/Akinetopsia) make his books great reads for the casually curious and really make it concrete how much of our reality is formed primarily in our heads.
One of the most interesting stories is about a man who lost his ability to intuitively recognize things and needs to reason about their features to find out what they are.
Whole excerpt here: http://www.odysseyeditions.com/EBooks/Oliver-Sacks/The-Man-W...