I'd maybe make a hypothesis that a large portion of the space is "bad" smelling stuff: smoke or garbage. When people had covid-induced parosmia, it almost always seemed to be bad smelling stuff.
I wonder if we search for the worst smell, via optimization, is does this make it a big, not very steep optimum? Or maybe all unknown smells are a little bad, but the worst smell is some familiar badness.
Still have it, intermittently. A sort of nameless-but-familiar "chemical" smell that comes and goes, along with any sense of taste. That is, I have bad days with no taste, just a chemical smell. Other days I have a pretty good sense of smell, generally with a good sense of taste.
Intriguingly some of the really unpleasant smells never get through to me - I could probably work at a sewage works now. Worryingly I have next to no ability to smell burning, though I do now get the smell of natural gas (or the additive used to make it smell).
There has been promising work on olfactory training, which you can do very inexpensively at home. If you can, I would consider seeing any ENT first to rule out polyps, etc.
This is something I'm still testing, so take it with a bucket of salt, but I've found that exposing myself to very strong samples of things that I was unable to smell made something click again and I started to smell them again. Seems like something in there needs to be retrained to odors.
That's the basic method of retraining. I've got a bunch of essential oils in tiny jars and I regularly take a 20 second sniff of each whilst thinking strongly about the smell in context. For example, when I smell the lavender oil I recall the garden at my grandma's house which obviously was full of lavender. It's definitely helping, but there are still a lot of gaps.
I'm convinced that over the decades we'll continue to be a little surprised but just how much of our body-machinery is doing jobs of self-calibration, regulation, and safety-interlocks.
That was exactly my thought when reading the article and my personal experience with Covid. For a couple weeks, I perceived a persistent smell of something burning.
A smell of burning was how I suspected I had COVID the last time around. I was around some machines, I had to have someone else sniff around and let me know that nothing was actually burning.
Same here, and it's still there. I can't smell or taste a random set of stuff, like cinnamon, poop/farts. What annoys me most is that female genitalia just taste like nothing, literally...
In addition to this, I sometimes smell scents that do not exist.
Super interesting! That would make sense, because a lot of the nose is presumably dedicated to smelling evolutionarily-relevant smells, most of which are "smells bad, avoid this". The method is very crude right now, but maybe with more fine-grained targetting we could better tune the smell profile.
And even good / bad is sometimes subjective and brain can adjust to it depend on whatever you like the taste for instance. Tell you this as a big fan of durian. Since there a lot of chemicals responsible for smell brain override reaction to fruit once you love the taste.
