I have bruxism, which means I clench my teeth and grind them when I sleep. This pretty much results in always having a closed mouth unless I’m talking or have a cold. I have to consciously try to keep my molars separated during the day. Luckily, I guess, I have no sinus issues, so I breathe almost exclusively through my nose unless I’m exercising, talking, or have a cold.
As far as the terrible stench business is concerned, as someone with a fully functioning sinus cavity, I can tell you that I can smell plenty whether I’m breathing through my nose or mouth. It’s all connected, and unless my sinuses are stuffed up with a cold or something, I can smell that stench no matter what. I imagine if someone is mouth breathing due to sinus troubles, their sense of smell may be a bit impaired anyway, and the sinus blockage may prevent mouth-breathed stenches from reaching scent glands. Lucky you!
Physically I have no problem with mouth breathing, but psychologically I feel like I’m eating the stench rather than just smelling it so I normally continue nose breathing.
I think the pertinent part of the OP was: “mouth agape, lower lip protruding.” That implies not only breathing through one’s mouth but also having no consciousness of one’s appearance. When I have a cold, I breathe through my mouth, but my mouth does not gape or hang open.
Well, not unless I’m really, really sick, and then I’m home anyway. And possibly asleep.
The person I saw did also have a vacant stare that added to my presumption of stupidity. But even then, we all have occasions where we daydream and our eyes lose focus.
I use the term mouthbreather as a general insult when I’m around fellow gamers, but I don’t think less of people who literally breathe through their mouth. The reason it came about as an insult, perhaps, is that when a guy goes slack-jawed over a woman, his mouth falls open and he starts like… panting, but slowly… simultaneously. This is pretty fucking unique (and squicky) to hear or witness.
I breathe through my nose all the time. I am definitely capable of mouth breathing but it chaps my lips up. I think I have some sinus issues because I have the only-one-nostril-open thing going on when I sleep on my side, and I love the easier-to-breathe feeling when I purposely flare my nostrils. Or possibly my nostrils are just smaller than average because I do have quite a smaller nose than most (it’s one of my only redeeming features). But breathing through my mouth makes it all dry and uncomfortable, so I don’t unless my nose is totally blocked up and I have no choice.
Og bless Nasonex.