I was waiting in line at the local post office. When my turn came, the clerk handed me a form to fill out. I stepped aside and the let the next person step up to the window, expecting I would be back talking to the clerk soon.
Well, not quite. Long having finished filling out the form, I listened to the conversation between the clerk and the customer. Customer: "But the card should work." Clerk: "Sorry, I don't see anything on my screen."
(The customer had inserted a post bank card into the reader.) This "it should work" went on a little longer, until the clerk said: "What does the display of the reader say?" Upon which the customer answered: "I can't read it. I always leave my glasses at home when I leave the house."
Aha... I offered to help, and bent over to look at the LCD display. There, in plain letters, it said: "Lesefehler" (read error). I informed the clerk and the customer about this, upon which the customer exclaimed: "This is annoying! This card hasn't been working right from the beginning, and still isn't!"