A quick sniff of the armpit area just lets one know whether it is fit to wear or not. If something has only been worn once, or for a little while, if can bear up to further wear.
Anyway - isn't it men who have the horrid habit of sniffing their socks to see if they will stand another day (or week?)
I hold my hands up I'm a sniffer, but I sniff lots of things, I sniff clothes when I'm ironing, I sniff a freshly changed duvet when I'm in bed. I like to smell things I used to suck my thumb and take one of my dads jumpers to bed with me it's a comfort thing!!