How do you know? All you know is that when your stink crosses a certain threshold, you can smell it. But you do not know where your theshold is.
The burden of proof is on you to prove the existence of the threshold. I'm not going to assume it exists.
I can see how you can get used to a house smell. You know how some people's houses smell different than others. I've noticed my clothes pick up the smell of any house I've been in the day before, especially if they're smokers. You can get used to the smell and not notice it on you. At my house, I don't notice a smell. Maybe other people can smell it on me, but I guess since I'm used to it, I don't notice it. Or there may not be any house smell at all on me.
But I don't see how you can get used to a stink coming from yourself unless you stink all the time. Because the moment you took a shower, you would notice the stink is gone and would notice it come back.
Also, why would your threshold for your own smell be high, but the threshold for someone elses smell be low? If you stink and someone else stinks just as bad as you, would you only notice their stink? That doesn't make sense.
The general opinion is that most people have the threshold for their own stink set pretty high. (It is the same reason bad breath abounds - people are actually unable to smell their own bad breath without making some deliberate attempts to do so.)
I can also smell if I have bad breath. Most people, from what I've noticed, who have bad breath, don't eat anything for long periods of time. Especially religious people who fast. If I went to church with them, their breath is enough to make me lose faith.
I usually eat something every hour or two, so I only have bad breath in the morning.
I also have a counter example. My friend and I go to the gym together and afterwards we usually go eat. Sometimes, but not always, after we're done at the gym, he says he has to go take a shower before we eat because he stinks. But I rarely smell anything unpleasant from him. He smells it before I do.
