The study of everything that is douchy. A true master of doucheronomy would do certian things as follows:
Wear gold chains
Complain bitterly about their food order and send it back
Stare at another person incessantly
Text on their phone like they were some kind of big shit
Have balls hanging from their pickup trucks
Wear sandals with a big toe loop(this could also be considered a faggot)
Talk loudly on cell phone in public situations
A person of theses traits will have a pungent odor of vinegar which is the main ingredient in douche. They will be unaware of their scent and think they smell pleasant, but in acutality they smell of douche. The only treatment to this malidy is to ingest large quantities of baking soda to counteract their douchocity. There is no cure. This ailment will eventually lead the victim to wear leather pants and drive a mini cooper. Research goes on to address this problem but we are years away from any viable cure.
Call poison control if you see anyone displaying the above traits.