I really, really love my job, but here are some observations I've made because I noticed a lot of customers do these things.

• Why do people go Christmas shopping with the people they're buying gifts for? Especially when it's something that can't be hidden easily? Then I get the lovely job of bagging the freaken huge Rockband in four hundred bags! If you want them to be surprised so badly - make a separate trip or something.
• When using the pin pad ... continuing to try to approve the payment or putting in your pin - I just can't get over customers who can't press the buttons correctly. They're like fight with the pin pad. It's not really that hard. If you notice the pen isn't working, then use your finger, but apply some pressure to the screen so it feels it. Pressing the edge of your card to the buttons will not work.