Where’s your bag, ma’am?
Oh, sorry. I forgot.
You do know that that will be a 5 cent charge for the bag, do you?
My friend, when conveying her experience on that fateful day in a Washington, DC check-out aisle:
I felt so small when I was standing there. One public shaming was enough. I always bring my bag with me now.
Check and mate. Economic incentives at work.
