For all practical purposes that's PRECISELY what it means, your brain blanks out the stimulus. You can technically still smell it, as the receptors pick up the stimulus, but your brain then filters it out. ISH I'm not a biologist, but someone here can describe precisly how it works.
I know what you're saying. Kinda like when something is touching you, you feel it at first, but your brain eventually blocks it out. Like when people don't know where they put their pencil, when it's right behind their ear.
Which is the point that Dave was rightly talking about. Just because YOU don't believe you smell doesn't mean others will hold the same opinion.
Regardless if your brain blocks out smells you "get used to", you're still able to smell them. If you walk into a stinky bathroom, the unpleasant odor will be offensive to you. If you stay there long enough, it will no longer be quite as offensive and you'll "get used to it". But your brain doesn't make you anosmatic. You can still smell it.
If you make a deliberate attempt to smell yourself, you'll be able to tell if you stink or not, since you know if it's different than what you smell like when you're clean.
EDIT: I also know precisely what Dave is talking about when he says the 'stale' smell.
"Stale" isn't a defined smell. If I said something smells like an orange, anyone who's smelled an orange would know what I'm talking about. "Stale" could mean two different things to two different people. Not all "stale" things smell alike.
I know where you're going with that, though. Since I don't recognize "stale" as a smell, that means I'm unable to smell it and I probably emit such an odor.
Just because I don't automatically equate a word with a smell, doesn't mean I wouldn't recognize a smell if I smelt it.
I'll make up a new one and act surprised when someone doesn't know the exact smell the word is assigned to.
Man you honestly are on some next level. How can something smell OPPOSITE of another smell, that's the most absurd thing I've ever heard. "it smells opposite of grass" REALLY! oh kay!
A bad smell is the opposite of a good smell. It's not perfect, but neither was your analogy.
When you shower you may smell 'good' who knows maybe you don't use fragranced soap so you just smell like your water? I don't know. You get used to that. When you start to 'smell bad' you don't 'smell opposite' of what you smell like when your clean.
But you can recognize the difference.
Here's some homework for you. Go look up what occurs within the body to make various smells that we find 'smell bad'. Then go and find out if this works the same way for all people. (I'll tell you it doesn't, not everyone smells the same when they 'smell bad' YOU get used to your OWN smells) It's YOU getting used to YOUR body smelling DIFFERENT ways. Not 'OPPOSITE' ways.
If someone doesn't use deodorant, you can smell it. And it smells the same for everybody.
As well I never said that my crotch smells good however since I practice a routine hygiene program and take care of the area I'm certain that it would never smell 'off putting' to any potential person... So it might not smell like the hugo boss or old spice shower gel that I use to wash my body when I'm in the shower after 24 hours but it sure wouldn't smell 'bad'.
It might. Even if I did take a shower every day, I wouldn't want to just stick my crotch in somebody's face without making sure it's clean. I would hope you'd do the same thing, cause you don't know what your crotch could smell like 24 whole hours after it's been cleaned.
Or do you do a daily crotch check just to make sure you keep a consistent neutral crotch smell?
As for brushing our teeth, I've read that dental plaque actually protects the tooth enamel against acids.
Here's a quote from the dental plaque wiki article.
The microorganisms present in dental plaque are all naturally present in the oral cavity, and are normally harmless. However, failure to remove plaque by regular tooth brushing means that they are allowed to build up in a thick layer. Those microorganisms nearest the tooth surface convert to anaerobic respiration; it is in this state that they start to produce acids.
The dental plaque creates the acids.