Me for one. Whenever I enter someone's house I notice the pervading smell/reek. My own house in fact if I've been away for a while. Stale smoke and cat dander are readily noticeable for me as I'm a smoker and have a bit of an allergy to cats. Nothing more stimulating for me than the reek of fresh baked chocolate chip cookies or, probably the most welcoming odor of all, fresh baked bread. Everybody's home has a distinctive odor/reek. Probably mostly unnoticeable to the residents. Well, at least to this old, retired cop's nose. I was always searching out distinctive odors such as drugs, burned skin, gun shot residue in the air, I tried to note and identify any odors I ran into. Most probably do not do that but, all notice odors that are pleasing or offensive.