IME, of which I have more than I should, people that are exposed to it as it starts leaking, often won’t notice it.
I remember one time getting home from work to find my ex sitting in the living room with no idea how strongly the house smelled like gas. Apparently she was leaning against the stove while she was on the phone and bumped one of the knobs.
Where I work, our stove is in a high traffic (and breezy) area. Between that and normal things like a pot over boiling, one of the pilot lights goes out a few times a week. I’d guess that, at least half the time, it’s not someone working in the area that notices it, but either someone walking into that area (with no olfactory fatigue) or me. For whatever reason, it can drift through the entire kitchen area and all the way to my office and I’ll notice it before any of them do.
And there’s no shortage of stories where a house, with people inside the entire time, fills up with enough gas that the resulting explosions makes the house not exist anymore
