We are used to many things and we are programmed to notice those that have some important meaning to us and ignore others. It is like cats that can’t taste sweetness - when do cats eat sugar? It is not in their usual diet, and if it makes its way in it doesn’t really matter, it is not poisonous it is just tasteless. It is not important to them.

I guess it is important for us to notice our bodily odors when they get unpleasant - it is time for a shower - fusty sweat can be irritating to skin, and maybe even more important, unpleasant odor can make us undesirable mate for possible partners, they could think we don’t have what it takes to produce healthy offspring and to care for a family if we don’t or can’t care for ourselves. And as a social animal we probably wouldn’t get to much positive attention from our pack if we stink to them which could lead us to the bottom of hierarchy, not a pleasant place to be. If we often stink from sweat we don’t take care of our hygiene enough and there has to be a reason for that, we are either sick or careless or totally unprepared for the climate we found ourselves in – none of it makes us a good companion. I bet that goes through everybody’s head when they ran into someone with intense, repulsive odor. Lucky we don’t have to sniff each others piss… ;)