The other night at Kroger, it was after hours and I was in the self-check lane. It wasn't a mystery shop, but not until all of my coupons had been scanned did I realize that I had left the house with no cash and no credit/debit cards. It was embarrassing, but the cashier over all of the lanes left the order open while I drove home & got my payment. I tied up that particular register for 25 minutes while I drove home & back. The cashier was patient and polite, which I appreciated. Still, I was embarrassed.