Recounting retail horror stories can be a fun pastime when you've long since moved on. They bring up a sense of bittersweet nostalgia and don't usually cause your brain to swell with rage the way that they used to. It's not that Karens didn't exist in the past, rather you weren't aware of their species name — back in the good ol' days, you just called them a regular swear word. Over the years, only the really ridiculous instances stay with you, and most of the other miserable stories slowly fad…