Apparently the same area of the brain that deals with the memory of directions is also linked with face recognition. Some people cannot remember faces. Obviously, there are degrees of this problem depending on how our brains are wired with face recognition software.

Some of us are completely unable to recognise someone we had dinner with a few evenings ago. But once we are filled in on the conversation we had we are able to recognise the person.

My wife, who is very observant has been disappointed with me several times on these Kathmandu streets when I have driven past her (with my mind somewhere else) without any signs of recognition. Clearly I have come to realize that together with my poor memory of directions and perhaps a compromised face recognition ability, I suffer from a mild prosopagnosia, which is also defined as facial blindness.

Prosopagnosia may also explain the situation when a Nepali baby brought up in his own Nepali environment has a hard time recognizing individual Caucasian faces because they may all, relatively speaking, "look the same" and vice versa. While studying medicine in Patiala in India, for me all Sardarjis with their beards and turbans initially looked alike.

In these days of MRI scanners, people with overt propsagnosia clearly show lesions on the underside of the temporal cortex of the brain when scanned. They say that the difference between the best face recognizers and the worst amongst the prosopagnosics is so pronounced that it is comparable to that between people with an IQ of 150 and those with an IQ of 50. But as with any bell curve, the vast majority are in the middle.

Severe, debilitating prosopagnosia is estimated to affect two percent of the population in the US. But relatively little thought is given to this problem compared to say dyslexia (remember Taree Zameen Par?). Teachers and others are increasingly aware of the special difficulties (and often the special gifts) that dyslexic children may have. But for people with severe face blindness, for now, there is not much else to do but share this problem with others who may suffer from this and rely on your ingenuity to get by in daily living. The famous British anthropologist Jane Goodall who suffers from this problem says she would be better able to recognise her individual chimpanzees if she did not have mild prosopagnosia.