When I was a teenager I had a "super smell" sense which seems pretty ordinary compared to what others here are saying: I could detect whether a used glass of drink was mine by smelling the saliva in the glass (in fact I found it shocking that my friends couldn't). My friends mocked me, I suppressed my ability, and now I'm not sure if I can't smell it anymore or I simply don't care.
I'd occasionally notice taking the wrong used glass by the smell and even know who used it if it was someone close. Lots of pheromones and stuff, nothing unusual about it. I wouldn't say it's a bad smell, I just don't like using cups after my relatives, close friends, or well, other people. Drinking after single attractive ladies being mostly non-weird.
The sense does depend heavily on state of mind, and body, so sometimes I'd only notice when already drinking. Works better on people I know well.
