I don't have much of a sense of smell, but sometimes I have, I guess, olfactory hallucinations. When I was younger, I'd say I had a smell stuck in my nose. I've had the burning toast one. Lavender, which is supposed to be calming, is very unpleasant to me, sometimes making me wheeze. Some scented toiletries smell like something burning, which led to a bit of embarrassment when an employer changed after-shave. Some days I smell cigarette smoke very strongly in the house, even though it's been 3 years since anyone smoked here.

I also have some weird tastes. Like non-fresh onions tasting like soap. That turns out to be something "normal" folk have, too.

I know that some of our meds can alter the sense of smell. Also, I remember reading somewhere that the neural pathways associated with the sense of smell are close to the area of the brain associated with schizo-illnesses.