Wine & Gym Socks
Though my instructors did ensure me that there are no wrong answers when determining the nose of a wine, smelling wine, it seems, is not completely a subjective affair. It turns out aromas in wine are due to the presence of volatile compounds within wine... molecules that quickly turn to gas and stick to receptors in the nose, which are then perceived by the brain as scents. The concentrations and interactions of these volatile compounds do create fairly specific aromas. Maturation in oak barrels is known to impart vanilla flavors, for example, because vanillin is present in oak. Wine, therefore, literally smells of vanilla. Despite the specific correlation of scents to molecules, aromas can become muddled by our ability to smell and taste, as well the interactions of the volatile compounds with each other. Some molecules also have different aromas depending on their concentrations.
That being said, though "grandfather's gym socks" does not seem a common descriptor for wine aroma, there are some unusual smells that make the list. Cat pee, petroleum, diesel, tar and plastic are among them. From what I can tell, really unpleasant smells may indicate faults (it has to be drinkable after all), though some sources claim scents such as these can can indicate a high quality wine. As they say, "The heart wants what it wants." I guess that goes for the nose as well. It seems for some the nose wants cat pee.