There's a guy who i work with, young fella, flatting. Often has a manky smell about him, but it's not BO, it's that smell you get when you leave a load of clothes in the washing machine after it's done for too long before hanging them out. Or if they take too long to dry on the line when the weather is bad.
I just stand next to him, sniff loudly and go "Bro..... you stink! - did you forget the washing was in the machine?", and he goes "Whaaa......" then i see him an hour later with a different shirt on (he's popped home to change - so credit for that). How do you not notice that shit when you're putting your clothes on?