The thing is with smell is, it's basically a highly complex, involved diff tool. If you're surrounded by the same smells constantly, you won't pick up the smells. The body odour you express becomes the status quo.

For me to be able to smell my own body odour, they'd have to be a point in time where I didn't have body odour. And if my BO is so wretched I don't need to put my nose into my arm pit to smell it (I challenge anyone to disagree with me that they don't do an arm pit sniff test to gauge their cleanliness) well, throw me into a fucking lake.

Of course, some people may have more delicate smells than most. Or not at all. I don't know where I sit. But I've got a 100% success rate in never being told 'my dude, you smell like an over ripe peach', so I think I'm doing OK. Or my friends are part of a dasteredly ruse to forever keep me single.