Identifying aromas is not humanly impossible but the amount of existent aromas (divided in 3 types) is huge and hard to be evaluated or even recognized in its totality.
When tasting a wine it is possible to indentify certain memories and, sometimes, even travel in time. This is due to the aromas, which are engraved in our brain through a natural mechanism to identify aromas.
We do not find the same in a wine, i.e., the sensibility is different from person to person. For some, identifying green apple or banana’s aromas in a wine is quite easy, but to find caramel or mushroom aromas might be extremely difficult. And vice-versa.
As we grow old, we obviously lose olfactory capacity. Nonetheless, the more it is trained, the less is that lost. In order to have an excelent olfact we have to practice a lot.
A good way to do it is to start paying attention to every smell and odor in our day-to-day routine. I remember my first sensorial analysis class. The teacher used to tell us to smell everything we could touch (from pens to pencils, to glass, to our skin, everything).
Trying to visualize an image for each smell or odor is also quite important and, if possible, to write it down. Trust me, it will help you memorizing.
In this context, the best tip I can give you is: Taste, taste, taste!
Cheers!