The Scent of Life
The Nobel prize for Medicine-2004 is given to two scientists for their effiot in decoding the mystery of the most exotic human sense of smell. The scientists, Dr. Richard Axel, and Linda B. Buck from Seattle USA discovered how neurons send information about odours and pheromones to our brain that helps us to memorize and recall most of the odours. It is interesting that many a times we have felt a sense of 'deja vu' when we smell an odour. They used a molecular-genetic toolbox to analyze the olfactory system based on its information storage mechanism. Neural circuits and biologocal architecture of the information flow network was studied. The most revealing aspect of the study is that the information about odour triggers emotional and psychological behaviors that create distinct perceptions for each of the odours. This is significant considering the fact that our brain can remember each of over 10000 odours, that too very uniquely.
DEJA VU SMELLS
Paint [water color]: I can clearly remember the first time I painted.
Paint [Emulsion]: Hmmm, I really like the smell of fresh paint...remember when my father got our old scooter painted.
Petrol: Another of those 'I get hooked on to' smell. All the wait standing in front of the scooter when the petrol tank in the petrol bunk was open was worth the wait.
Diesel: This is nauseating, because I never enjoyed sitting near the engine and gear lever of the bus.
Ash: The Shiva temple vibhuthi(ash) has a special smell
Sandal paste: The Guruvayur temple (Kerala) sandal paste is unique.
Mustard oil: Oh..the fried Puri Bhajji that I ate at Agra railway station during my trip to New Delhi in 1994.

Some of my friends have some aversions to some smell..like one of them threw up when he smelt anything that smells close to jasmine flower. same with the smell of oil.

Ig Nobel awards for "smell" any one??
and of course...the smell of those distinct farts.Well such a career option is available[Worlds Worst Job as a Dysentery Stool-Sample Analyzer]..some very pungent, some fruity..I will not be surprised to know people can identify with what they ate with the smell of their farts. Which fart made them smell bad? or which fart gave them a pleasant experience? Though it is a very unpleasant experience for the ones around you

Its so wonderful to learn how our senses are more important to our survival. Ask a person who survived the Bhopal gas tragedy or a bombing attack.
References: research abstract