Funny you say that, because one thing that always irritates me is perfumes. It bothers me when someone has been through a building within the last hour or two wearing perfume. When I ride my bike, I am frequently struck by the synthetic smells coming off the pedestrians I pass. Busy areas are really offputting because of the mishmash of perfume smells. Yet still I can't conclusively pin a fart on a culprit.