Duality is everywhere. Everything in life has a flip-side. Even flip-flops. (You know, thong sandals.)
They're called "trip-kills." They have a wonderful tendency of dangling off the toe at just the right angle to catch your next step and send you into a drunken stumble when your blood alcohol level is flat-lined. Or, the thong even occasionally likes to cling between your toes when you're trying to quickly doff them, triggering that awkward lean as you take your next step like the be-flip-flipped foot is loosely glued to the ground. And a dark pair with their low-profile can be a curse inducing hazard to the unwary pedestrian trying to navigate a dim hallway. Good times!
Yes, indeedy! Flip-flops aren't flip-flops at all, betimes. They have that dual nature as trip-kills, also. Don't forget it.
Besides trip-kills, might there be other articles of clothing or household items that often fail to conceal their dual identity? Don't keep it a secret. Out the offending inanimate object and let's all be safer for it.